Adilbek's house is located on a street which can be represented as the OX axis. This street is really dark, so Adilbek wants to install some post lamps to illuminate it. Street has n positions to install lamps, they correspond to the integer numbers from 0 to n - 1 on the OX axis. However, some positions are blocked and no post lamp can be placed there.

There are post lamps of different types which differ only by their power. When placed in position x, post lamp of power l illuminates the segment [x; x + l]. The power of each post lamp is always a positive integer number.

The post lamp shop provides an infinite amount of lamps of each type from power 1 to power k. Though each customer is only allowed to order post lamps of exactly one type. Post lamps of power l cost a_l each.

What is the minimal total cost of the post lamps of exactly one type Adilbek can buy to illuminate the entire segment [0; n] of the street? If some lamps illuminate any other segment of the street, Adilbek does not care, so, for example, he may place a lamp of power 3 in position n - 1 (even though its illumination zone doesn't completely belong to segment [0; n]).

Input

The first line contains three integer numbers n, m and k (1 ≤ k ≤ n ≤ 10^6, 0 ≤ m ≤ n) — the length of the segment of the street Adilbek wants to illuminate, the number of the blocked positions and the maximum power of the post lamp available.

The second line contains m integer numbers s_1, s_2, ..., s_m (0 ≤ s_1 < s_2 < ... s_m < n) — the blocked positions.

The third line contains k integer numbers a_1, a_2, ..., a_k (1 ≤ a_i ≤ 10^6) — the costs of the post lamps.

Output

Print the minimal total cost of the post lamps of exactly one type Adilbek can buy to illuminate the entire segment [0; n] of the street.

If illumintaing the entire segment [0; n] is impossible, print -1.

Examples

Input

6 2 3
1 3
1 2 3


Output

6


Input

4 3 4
1 2 3
1 10 100 1000


Output

1000


Input

5 1 5
0
3 3 3 3 3


Output

-1


Input

7 4 3
2 4 5 6
3 14 15


Output

-1
import java.io.*;
import java.util.*;
//I am fading.......
//read the question correctly (is y a vowel? what are the exact constraints?)
//look out for SPECIAL CASES (n=1?) and overflow (ll vs int?)
public class Main
{
	public static void main(String[] args) throws Exception
	{
		int n=ni(),m=ni(),k=ni();
		boolean[]a=new boolean[2000001];
		int[]minor=new int[2000001];
		int[]b=nia(m);
		for(int i:b)
			a[i]=true;
		for(int j=0,l=0; j<2000001; j++)
		{
			if(!a[j])
				l=j;
			minor[j]=l;
		}
		if(a[0])
		{
			sop(-1);
			return;
		}
		int[]costs=pnia(k);
		long minc=inf;
		for(int i=1; i<=k; i++)
		{
			boolean npos=false;
			long cost=0;
			for(int j=0; j<n; j=minor[j+i])
			{
				if(j==minor[j+i])
				{
					npos=true;
					break;
				}
				cost+=costs[i];
			}
			if(!npos)
				minc=Math.min(minc, cost);
		}
		if(minc!=inf)
			sop(minc);
		else
			sop(-1);
		System.out.print(output);
	}
	
	
	
	///////////////////////////////////////////
	///////////////////////////////////////////
	///template from here
	
	static class pair
	{
		int a,b;
		pair(){}
		pair(int c,int d){a=c;b=d;}
		@Override
		public int hashCode(){return (a+" "+b).hashCode();}
		@Override public boolean equals(Object c){if(a==((pair)c).a&&b==((pair)c).b)return true;return false;}
	}
	static interface combiner
	{
		public int combine(int a, int b);
	}
	static final int mod=1000000007;
	static final double eps=1e-7;
	static final long inf=100000000000000000L;
	static Reader in=new Reader();
	static StringBuilder output=new StringBuilder();
	static Random rn=new Random();
	public static void sort(int[]a)
	{
		int te;
		for(int i=0; i<a.length; i+=2)
		{
			te=rn.nextInt(a.length);
			if(i!=te)
			{
				a[i]^=a[te];
				a[te]^=a[i];
				a[i]^=a[te];
			}
		}
		Arrays.sort(a);
	}
	public static void sort(long[]a)
	{
		int te;
		for(int i=0; i<a.length; i+=2)
		{
			te=rn.nextInt(a.length);
			if(i!=te)
			{
			a[i]^=a[te];
			a[te]^=a[i];
			a[i]^=a[te];
			}
		}
		Arrays.sort(a);
	}
	public static void sort(double[]a)
	{
		int te;
		double te1;
		for(int i=0; i<a.length; i+=2)
		{
			te=rn.nextInt(a.length);
			if(i!=te)
			{
			te1=a[te];
			a[te]=a[i];
			a[i]=te1;
			}
		}
		Arrays.sort(a);
	}
	public static void sort(int[][]a)
	{
		Arrays.sort(a, new Comparator<int[]>()
		{
			public int compare(int[]a,int[]b)
			{
				if(a[0]>b[0])
					return -1;
				if(b[0]>a[0])
					return 1;
				return 0;
			}
		});
	}
	static int lowerbound(int[]a, int key)
	{
		/*
		 * returns index of smallest element larger than equal to given element between indices l and r inclusive
		 */
		int low=0,high=a.length-1,mid=(low+high)/2;
		while(low<high)
		{
			if(a[mid] >= key)
				high=mid;
			else
				low=mid+1;
			mid=(low+high)/2;
		}
		return mid;
	}
	static int upperbound(int[]a, int key)
	{
		int low=0,high=a.length-1,mid=(low+high+1)/2;
		while(low<high)
		{
			if(a[mid] <= key)
				low=mid;
			else
				high=mid-1;
			mid=(low+high+1)/2;
		}
		return mid;
	}
	static int lowerbound(int[]a, int l, int r, int key)
	{
		int low=l,high=r,mid=(low+high)/2;
		while(low<high)
		{
			if(a[mid] >= key)
				high=mid;
			else
				low=mid+1;
			mid=(low+high)/2;
		}
		return mid;
	}
	static int upperbound(int[]a, int l, int r, int key)
	{
		/*
		 * returns index of largest element smaller than equal to given element
		 */
		int low=l,high=r,mid=(low+high+1)/2;
		while(low<high)
		{
			if(a[mid] <= key)
				low=mid;
			else
				high=mid-1;
			mid=(low+high+1)/2;
		}
		return mid;
	}
	
	void sort(pair[]a)
	{
		Arrays.sort(a,new Comparator<pair>()
				{
			@Override
			public int compare(pair a,pair b)
			{
				if(a.a>b.a)
					return 1;
				if(b.a>a.a)
				return -1;
				return 0;
			}
				});
	}
	static int log2n(long a)
	{
		int te=0;
		while(a>0)
		{
			a>>=1;
			++te;
		}
		return te;
	}
	static class vecti
	{
		int a[],size;
		vecti(){a=new int[10];size=0;}
		vecti(int n){a=new int[n];size=0;}
		public void add(int b){if(++size==a.length)a=Arrays.copyOf(a, 2*size);a[size-1]=b;}
		public void sort(){Arrays.sort(a, 0, size);}
		public void sort(int l, int r){Arrays.sort(a, l, r);}
	}
	static class vectl
	{
		long a[];
		int size;
		vectl(){a=new long[10];size=0;}
		vectl(int n){a=new long[n];size=0;}
		public void add(long b){if(++size==a.length)a=Arrays.copyOf(a, 2*size);a[size-1]=b;}
		public void sort(){Arrays.sort(a, 0, size);}
		public void sort(int l, int r){Arrays.sort(a, l, r);}
	}
	static class vectd
	{
		double a[];
		int size;
		vectd(){a=new double[10];size=0;}
		vectd(int n){a=new double[n];size=0;}
		public void add(double b){if(++size==a.length)a=Arrays.copyOf(a, 2*size);a[size-1]=b;}
		public void sort(){Arrays.sort(a, 0, size);}
		public void sort(int l, int r){Arrays.sort(a, l, r);}
	}
	//output functions////////////////
	static void pr(Object a){output.append(a+"\n");}
	static void pr(){output.append("\n");}
	static void p(Object a){output.append(a);}
	static void pra(int[]a){for(int i:a)output.append(i+" ");output.append("\n");}
	static void pra(long[]a){for(long i:a)output.append(i+" ");output.append("\n");}
	static void pra(String[]a){for(String i:a)output.append(i+" ");output.append("\n");}
	static void pra(double[]a){for(double i:a)output.append(i+" ");output.append("\n");}
	static void sop(Object a){System.out.println(a);}
	static void flush(){System.out.println(output);output=new StringBuilder();}
	//////////////////////////////////
	//input functions/////////////////
	static int ni(){return Integer.parseInt(in.next());}
	static long nl(){return Long.parseLong(in.next());}
	static String ns(){return in.next();}
	static double nd(){return Double.parseDouble(in.next());}
	static int[] nia(int n){int a[]=new int[n];for(int i=0; i<n; i++)a[i]=ni();return a;}
	static int[] pnia(int n){int a[]=new int[n+1];for(int i=1; i<=n; i++)a[i]=ni();return a;}
	static long[] nla(int n){long a[]=new long[n];for(int i=0; i<n; i++)a[i]=nl();return a;}
	static String[] nsa(int n){String a[]=new String[n];for(int i=0; i<n; i++)a[i]=ns();return a;}
	static double[] nda(int n){double a[]=new double[n];for(int i=0; i<n; i++)a[i]=nd();return a;}
	//////////////////////////////////
	//some utility functions
	static void exit(){System.exit(0);}
	static int min(int... a){int min=a[0];for(int i:a)min=Math.min(min, i);return min;}
	static int max(int... a){int max=a[0];for(int i:a)max=Math.max(max, i);return max;}	
	static int gcd(int... a){int gcd=a[0];for(int i:a)gcd=gcd(gcd, i);return gcd;}	
	static String pr(String a, long b){String c="";while(b>0){if(b%2==1)c=c.concat(a);a=a.concat(a);b>>=1;}return c;}
	static long powm(long a, long b, long m){long an=1;long c=a;while(b>0){if(b%2==1)an=(an*c)%m;c=(c*c)%m;b>>=1;}return an;}
	static int gcd(int a, int b){if(b==0)return a;return gcd(b, a%b);}
	static class Reader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;
        public Reader() {
            reader = new BufferedReader(new InputStreamReader(System.in), 32768);
            tokenizer = null;
        }
        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
    }
}