Your friend Mishka and you attend a calculus lecture. Lecture lasts n minutes. Lecturer tells ai theorems during the i-th minute.

Mishka is really interested in calculus, though it is so hard to stay awake for all the time of lecture. You are given an array t of Mishka's behavior. If Mishka is asleep during the i-th minute of the lecture then ti will be equal to 0, otherwise it will be equal to 1. When Mishka is awake he writes down all the theorems he is being told — ai during the i-th minute. Otherwise he writes nothing.

You know some secret technique to keep Mishka awake for k minutes straight. However you can use it only once. You can start using it at the beginning of any minute between 1 and n - k + 1. If you use it on some minute i then Mishka will be awake during minutes j such that <image> and will write down all the theorems lecturer tells.

You task is to calculate the maximum number of theorems Mishka will be able to write down if you use your technique only once to wake him up.

Input

The first line of the input contains two integer numbers n and k (1 ≤ k ≤ n ≤ 105) — the duration of the lecture in minutes and the number of minutes you can keep Mishka awake.

The second line of the input contains n integer numbers a1, a2, ... an (1 ≤ ai ≤ 104) — the number of theorems lecturer tells during the i-th minute.

The third line of the input contains n integer numbers t1, t2, ... tn (0 ≤ ti ≤ 1) — type of Mishka's behavior at the i-th minute of the lecture.

Output

Print only one integer — the maximum number of theorems Mishka will be able to write down if you use your technique only once to wake him up.

Example

Input

6 3
1 3 5 2 5 4
1 1 0 1 0 0


Output

16

Note

In the sample case the better way is to use the secret technique at the beginning of the third minute. Then the number of theorems Mishka will be able to write down will be equal to 16.
import java.io.*;
     
     
     
     
    import java.math.*;
    import java.util.*;
import java.util.concurrent.DelayQueue;    
          public class Main
           {
            private InputStream is;
            private PrintWriter out;
            static int MOD = (int)(1e9+7);
            ArrayList<Integer>[] amp;
            public static void main(String[] args) throws Exception
            {
                new Thread(null, new Runnable()
                {
                public void run()
                {
                    try {
         } catch (Exception e)
                    {
                        System.out.println(e);
                    }
                }
            }, "1", 1 << 26).start();
                new Main().soln();
            }
            char ch[][];
            static ArrayList<Integer>[] g=new ArrayList[100001];
            static ArrayList<Integer> ar[];
            static long ok[];    
            static int phi[]=new int[500005];
            static int dp[][];
            void solve()
            {
            	int n = ni();
            	int k = ni();
            	int a[]=na(n);
            	int t[]=na(n);
            	int pre[]=new int[n];
            	for(int i=0;i<n;i++)
            	{
            		if(i==0)
            		{
            			if(t[i]==1)
            				pre[i]=a[i];
            		}
            		else
            		{
            			if(t[i]==1)
            				pre[i]+=a[i];
            			pre[i]+=pre[i-1];
            		}
            	}
            	int suf[]=new int[n];
            	for(int i=n-1;i>=0;i--)
            	{
            		if(i==n-1)
            		{
            			if(t[i]==1)
            				suf[i]=a[i];
            		}
            		else
            		{
            			if(t[i]==1)
            				suf[i]+=a[i];
            			suf[i]+=suf[i+1];
            		}
            	}
            	int sum[]=new int[n];
            	for(int i=0;i<n;i++)
            	{
            		if(i==0)
            			sum[i]=a[i];
            		else
            			sum[i]=sum[i-1]+a[i];
            	}
            	int max=0;
            	for(int i=0;i<n;i++)
            	{
            		int x=i+k-1;
            		if(x>=n)break;
            		int lol=sum[x];
            		if(i-1>=0)
            			lol-=sum[i-1];
            		int tmp=lol;
            		if(i-1>=0)
            			tmp+=pre[i-1];
            		if(x+1<n)
            			tmp+=suf[x+1];
            		max=Math.max(max, tmp);
            	}
            	out.println(max);
            }
             
            public static long query(int v,int start,int end,int l,int r,int x)
            {
            	if(r < start || end < l)
                {
                    return 0;
                }
                if(l <= start && end <= r)
                {
                    return (tre[v]);
                }
                int mid = (start + end) / 2;
                long p1 = query(2*v, start, mid, l, r,x);
                long p2 = query(2*v+1, mid+1, end, l, r,x);
                return p1+p2;	
            }
            public static void update(int v,int tl,int tr,long l,long harami2)
            {
            	if(tl==tr)
                {
                    tre[v]=harami2;
                }
                else
                {
                    int mid=(tl+tr)/2;
                    if(tl <= l &&l <= mid)
                    {
                        update(2*v,tl, mid, l, harami2);
                    }
                    else
                    {
                        update(2*v+1,mid+1,tr, l, harami2);
                    }
                    tre[v]=tre[2*v]+tre[2*v+1];
                }
            }
            static long tre[]=new long[8000005];
            static ArrayList<String> dictionary = new ArrayList();
            public static void wordBreakUtil(String s,int n,String result)
            {
            	for(int i=1;i<=n;i++)
            	{
            		String prefix = s.substring(0,i);
            		if(dictionary.contains(prefix))
            		{
            			if(i==n)
            			{
            				result+=prefix;
            				System.out.println(result);
            				return;
            			}
            			wordBreakUtil(s.substring(i),n-i,result+prefix+" ");
            		}
            	}
            }
            public static void permute(char s[],int l,int r)
            {
            	if(l==r)
            	{
            		System.out.println(new String(s));
            	}
            	else
            	{
            		for(int i=l;i<=r;i++)
            		{
            			char temp=s[i];
            			s[i]=s[l];
            			s[l]=temp;
            			permute(s,l+1,r);
            			temp=s[i];
            			s[i]=s[l];
            			s[l]=temp;
            		}
            	}
            }
            public static void StockSpan(int a[],int n)
            {
            	Stack<Integer> st = new Stack();
            	st.push(0);
            	int S[]=new int[n];
            	S[0]=1;
            	for(int i=1;i<n;i++)
            	{
            		while(!st.isEmpty()&&a[st.peek()]<=a[i])
            			st.pop();
            		S[i]=(st.isEmpty())?(i+1):(i-st.peek());
            		st.push(i);
            	}
            	for(int i=0;i<n;i++)
            		System.out.print(S[i]+" ");
            }
            
            
            public static void MaxSum(int a[][],int r,int c)
            {
            	int ans=0;
            	for(int i=0;i<r/2;i++)
            	{
            		for(int j=0;j<c/2;j++)
            		{
            			int r1=i;
            			int c1=j;
            			int r2=r-i-1;
            			int c2=c-j-1;
            			ans+=Math.max(Math.max(a[r1][c1],a[r1][c2]),Math.max(a[r2][c1],a[r2][c2]));
            		}
            	}
            	System.out.println(ans);
            
            }
            
            
            public static void Dia(int a[][],int row,int col)
            {
            	for(int line=1;line<=(row+col-1);line++)
            	{
            		int start_col = Math.max(0,line-row);
            		int count = Math.min(line,Math.min(row,col-start_col));
            		for(int j=0;j<count;j++)
            		{
            			System.out.print(a[Math.min(row,line)-j-1][start_col+j]+" ");
            		}
            		System.out.println();
            	}
            }

			public static void AntiClock(int a[][],int n)
            
            {
            	for(int i=0;i<n;i++)
            	{
            		for(int j=i;j<n;j++)
            		{
            			int tmp=a[i][j];
            			a[i][j]=a[j][i];
            			a[j][i]=tmp;
            		}
            	}
            	for(int i=0;i<n/2;i++)
            	{
            		for(int j=0;j<n;j++)
            		{
            			int tmp=a[i][j];
            			a[i][j]=a[n-1-i][j];
            			a[n-1-i][j]=tmp;
            		}
            	}
            	
            }
            
           
            
            
            
            
            public static long pr(long x,long y,long m)
            {
            	if(y==0)
            		return 1;
            	long p = pr(x,y/2,m);
            	p=(p*p)%m;
            	return(y%2==0)?(p):(x*p%m);
            }
            public static long GCD(long x,long y)
            {
            	if(y==0)
            		return x;
            	else
            		return GCD(y,x%y);
            }
            
            public static void print(ArrayList<Integer> ar)
            {
            	Collections.sort(ar,Collections.reverseOrder());
            	System.out.println("Yes");
            	for(int x:ar)
            	{
            		System.out.print(x+" ");
            	}
            	return;
            }
            public static void LOL()
            {
            	/*int a[]=new int[5];
            	a[0]=2;a[1]=1;a[2]=4;a[3]=3;a[4]=5;
            	 System.out.println(LIS(a,5));
            	 int n=5;
            	 int dp[]=new int[n];
            	 for(int i=0;i<n;i++)
            		 dp[i]=1;
            	 
            	 int backtrack[]=new int[n];
            	 Arrays.fill(backtrack,-1);
            	 for(int i=1;i<n;i++)
            	 {
            		 for(int j=0;j<i;j++)
            		 {
            			 if(dp[j]+1>dp[i]&&a[j]<a[i])
            			 {
            				 dp[i]=dp[j]+1;
            				 backtrack[i]=j;
            			 }
            		 }
            	 }
            	 int index=-1;
            	 int max=0;
            	 for(int i=0;i<n;i++)
            	 {
            		 if(max<dp[i])
            		 {
            			 index=i;
            			 max=dp[i];
            		 }
            	 }
            	 
            	 int tmp=index;
            	 Stack<Integer> st=new Stack();
            	 while(tmp>=0)
            	 {
            		 st.push(a[tmp]);
            		 tmp=backtrack[tmp];
            	 }
            	 while(!st.isEmpty())
            	 {
            		 out.print(st.pop()+" ");
            	 }
            /*	int n=150;
            	int ugly[]=new int[n+1];
            	ugly[0]=1;
            	int next_multiple_of_2=2;
            	int next_multiple_of_3=3;
            	int next_multiple_of_5=5;
            	int i2=0;int i3=0;int i5=0;
            	for(int i=1;i<n;i++)
            	{
            		int min=Math.min(next_multiple_of_5, Math.min(next_multiple_of_3, next_multiple_of_2));
            		ugly[i]=min;
            		if(min==next_multiple_of_2)
            		{
            			i2++;
            			next_multiple_of_2=ugly[i2]*2;
            		}
            		if(min==next_multiple_of_3)
            		{
            			i3++;
            			next_multiple_of_3=ugly[i3]*3;
            		}
            		if(min==next_multiple_of_5)
            		{
            			i5++;
            			next_multiple_of_5=ugly[i5]*5;
            		}
            	}
            	System.out.println(ugly[n-1]);
            	
            	int t=ni();
            	while(t-->0)
            	{
            		long n=nl();
            		int a[]=new int[4];
            		a[0]=2;
            		a[1]=3;
            		a[2]=5;
            		a[3]=7;
            		long sucks=0;
            		for(int i=0;i<(1<<4);i++)
            		{
            			int count=0;
            			long curr=1;
            			for(int j=0;j<4;j++)
            			{
            				int x=i;
            				x&=(1<<j);
            				if(x>0)
            				{
            					curr*=(long)a[j];
            					count++;
            				}
            			}
            			if(count==0)
            				continue;
            			if(count%2==1)
            			{
            				sucks+=(n/curr);
            			}
            			else
            			{
            				sucks-=(n/curr);
            			}
            		}
            		out.println(n-sucks);
            	}
            	String s1=ns();
            	String s2=ns();
            	int m=s1.length();int n=s2.length();
            	int dp[][]=new int[m+1][n+1];
            	for(int i=0;i<=m;i++)
            	{
            		for(int j=0;j<=n;j++)
            		{
            			if(i==0)
            				dp[i][j]=j;
            			else if(j==0)
            				dp[i][j]=i;
            			else if(s1.charAt(i-1)==s2.charAt(j-1))
            				dp[i][j]=dp[i-1][j-1];
            			else
            				dp[i][j]=1+Math.min(dp[i-1][j-1],Math.min(dp[i-1][j],dp[i][j-1]));
            		}
            	}*/
            }
            public static int edit(String s1,String s2,int m,int n)
            {
            	if(m==0)
            		return n;
            	if(n==0)
            		return m;
            	if(s1.charAt(m-1)==s2.charAt(n-1))
            		return edit(s1,s2,m-1,n-1);
            	return 1+Math.min(edit(s1,s2,m,n-1),Math.min(edit(s1,s2,m-1,n),edit(s1,s2,m-1,n-1)));
            }
            static int max=1;
            public static int LIS(int a[],int n  )
            {
            	if(n==1)
            		return 1;
            	int res=1;
            	int max_ending_here=1;
            	for(int i=1;i<n;i++)
            	{
            		res=LIS(a,i);
            		if(a[i-1]<a[n-1]&&res+1>max_ending_here)
            			max_ending_here=res+1;
            	}
            	max=Math.max(max,max_ending_here);
            	return max_ending_here;
            }
            static boolean visi1[];
            static int cont=0;
            static int para[];
            public static void dfs(int curr,int pr)
            {
            	visi1[curr]=true;
            	
            	int trees=0;
            	for(int x:g[curr])
            	{
            		if(!visi1[x]&&x!=pr)
            		{
            			trees++;
            			dfs(x,pr);
            		}
            	}
            	if(trees==0)cont++;
            }
            
            static boolean visited[][];
			static int a[][];
            
          /* public static int find(int v,int start,int end,int l,int r)
            {
                if(r < start || end < l)
                {
                    return Integer.MIN_VALUE;
                }
                if(l <= start && end <= r)
                {
                    return (tre[v]);
                }
                int mid = (start + end) / 2;
                int p1 = find(2*v, start, mid, l, r);
                int p2 = find(2*v+1, mid+1, end, l, r);
                return Math.max(p1, p2);          
            }
            static int tre[]=new int[4000005];
            public static void Update(int v,int tl,int tr,int index,int val)
            {
                if(tl==tr)
                {
                    tre[v]=val;
                }
                else
                {
                    int mid=(tl+tr)/2;
                    if(tl <= index &&index <= mid)
                    {
                        Update(2*v,tl, mid, index, val);
                    }
                    else
                    {
                        Update(2*v+1,mid+1,tr, index, val);
                    }
                    tre[v]=(Math.max(tre[2*v],tre[2*v+1]));
                }
            }
            */
            
            static int d,x,y;
            static void exE(int a,int b)
            {
            	if(b==0)
            	{
            		d=a;
            		x=1;
            		y=0;
            	}
            	else
            	{
            		exE(b,a%b);
            		int tmp=x;
            		x=y;
            		y=tmp - (a/b)*y;
            	}
            }
            boolean isPrime(int x)
                {
                if(x==0||x==1)
                    return false;
                for(int i = 2;i*1L*i<=x;i++) if(x%i==0) return false;
                return true;
            }
            int  p ;
            long modInverse(long a, long mOD2){
                return  power(a, mOD2-2, mOD2);
            }
            long power(long x, long y, long m)
            {
            if (y == 0)
            return 1;
            long p = power(x, y/2, m) % m;
            p = (p * p) % m;
        
            return (y%2 == 0)? p : (x * p) % m;
            }
            public static long gcd(long a, long b){
                if(b==0) return a;
                return gcd(b,a%b);
            }
            class Pair1 implements Comparable<Pair1>{
                long a;
               
                double c;
                long b;
                Pair1(long x,double z,long y){
                this.a=x;
                              this.c=z;
                              this.b=y;
                }
                public int hashCode() {
                    return Objects.hash();
                }
                
                @Override
                public int compareTo(Pair1 arg0) {
                    if(c!=arg0.c)
                	return (int)(c-arg0.c);
                    else
                    	return (int)(arg0.b-b);
                }    
            }
            long power(long x, long y, int mod){
                long ans = 1;
                while(y>0){
                    if(y%2==0){
                        x = (x*x)%mod;
                        y/=2;
                    }
                    else{
                        ans = (x*ans)%mod;
                        y--;
                    }
                }
                return ans;
            }
            void soln() {
                is = System.in;
                out = new PrintWriter(System.out);
                long s = System.currentTimeMillis();
                solve();
                out.flush();
            }
             private byte[] inbuf = new byte[1024];
            public int lenbuf = 0, ptrbuf = 0;
            private int readByte() {
                if (lenbuf == -1)
                    throw new InputMismatchException();
                if (ptrbuf >= lenbuf) {
                    ptrbuf = 0;
                    try {
                        lenbuf = is.read(inbuf);
                    } catch (IOException e) {
                        throw new InputMismatchException();
                    }
                    if (lenbuf <= 0)
                        return -1;
                }
                return inbuf[ptrbuf++];
            }
            private boolean isSpaceChar(int c) {
                return !(c >= 33 && c <= 126);
            }
            private int skip() {
                int b;
                while ((b = readByte()) != -1 && isSpaceChar(b))
                    ;
                return b;
            }
            private double nd() {
                return Double.parseDouble(ns());
            }
            private char nc() {
                return (char) skip();
            }
            private String ns() {
                int b = skip();
                StringBuilder sb = new StringBuilder();
                while (!(isSpaceChar(b))) {
                    sb.appendCodePoint(b);
                    b = readByte();
                }
                return sb.toString();
            }
            private char[] ns(int n) {
                char[] buf = new char[n];
                int b = skip(), p = 0;
                while (p < n && !(isSpaceChar(b))) {
                    buf[p++] = (char) b;
                    b = readByte();
                }
                return n == p ? buf : Arrays.copyOf(buf, p);
            }
            private int[][] nm(int n, int m) {
                int[][] map = new int[n][m];
                for (int i = 0; i < n; i++)
                {
                    for(int j=0;j<m;j++)
                        map[i][j]=ni();
                }
                return map;
            }
            private int[] na(int n) {
                int[] a = new int[n];
                for (int i = 0; i < n; i++)
                    a[i] = ni();
                return a;
            }
            private int ni() {
                int num = 0, b;
                boolean minus = false;
                while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
                    ;
                if (b == '-') {
                    minus = true;
                    b = readByte();
                }
                while (true) {
                    if (b >= '0' && b <= '9') {
                        num = num * 10 + (b - '0');
                    } else {
                        return minus ? -num : num;
                    }
                    b = readByte();
                }
            }
            private long nl() {
                long num = 0;
                int b;
                boolean minus = false;
                while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
                    ;
                if (b == '-') {
                    minus = true;
                    b = readByte();
                }
                while (true) {
                    if (b >= '0' && b <= '9') {
                        num = num * 10 + (b - '0');
                    } else {
                        return minus ? -num : num;
                    }
                    b = readByte();
                }
            }
            private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
            private void tr(Object... o) {
                if (!oj)
                    System.out.println(Arrays.deepToString(o));
            }
        }  