The only difference between easy and hard versions is the length of the string.

You are given a string s and a string t, both consisting only of lowercase Latin letters. It is guaranteed that t can be obtained from s by removing some (possibly, zero) number of characters (not necessary contiguous) from s without changing order of remaining characters (in other words, it is guaranteed that t is a subsequence of s).

For example, the strings "test", "tst", "tt", "et" and "" are subsequences of the string "test". But the strings "tset", "se", "contest" are not subsequences of the string "test".

You want to remove some substring (contiguous subsequence) from s of maximum possible length such that after removing this substring t will remain a subsequence of s.

If you want to remove the substring s[l;r] then the string s will be transformed to s_1 s_2 ... s_{l-1} s_{r+1} s_{r+2} ... s_{|s|-1} s_{|s|} (where |s| is the length of s).

Your task is to find the maximum possible length of the substring you can remove so that t is still a subsequence of s.

Input

The first line of the input contains one string s consisting of at least 1 and at most 2 ⋅ 10^5 lowercase Latin letters.

The second line of the input contains one string t consisting of at least 1 and at most 2 ⋅ 10^5 lowercase Latin letters.

It is guaranteed that t is a subsequence of s.

Output

Print one integer — the maximum possible length of the substring you can remove so that t is still a subsequence of s.

Examples

Input


bbaba
bb


Output


3


Input


baaba
ab


Output


2


Input


abcde
abcde


Output


0


Input


asdfasdf
fasd


Output


3
import java.io.*;
import java.util.*;
import java.text.*;
import java.lang.*;
import java.math.*;
 
public class Main{
    
    static int f(int i,int j) {
    	if(i==0) {   //up
    		if(j==0 || j==1) {
    			return 1;
    		}
    	}
    	else if(i==1) {
    		if(j==0 || j==1) {
    			return -1;
    		}
    	}
    	else if(i==3) {
    		if(j==2 || j==3) {
    			return 1;
    		}
    	}
    	else {
    		if(j==2 || j==3) {
    			return -1;
    		}
    	}
       return 0;
    }
       public void solve () {
        InputReader in = new InputReader(System.in);
        PrintWriter pw = new PrintWriter(System.out); 
	    char s[]=in.nextLine().toCharArray();
	    char t[]=in.nextLine().toCharArray();
	    int suf[]=new int [s.length+5];
	    int cnt=0;
	    Arrays.fill(suf, s.length);
	    for(int i=s.length-1;i>=0;i--) {
	    	if(t.length-1-cnt>=0 &&  s[i]==t[t.length-1-cnt]) {
	    		suf[t.length-1-cnt]=i;
	    		cnt++;
	    	}
	    }
	    long ans=suf[0];
	    cnt=0;
	    for(int i=0;i<s.length;i++) {
	    	if(t.length-1-cnt>=0 &&  s[i]==t[cnt]) {
	    		ans=Math.max(ans, suf[cnt+1]-i-1);
	    		cnt++;
	    	}
	    }
	    pw.print(ans);
        pw.flush();
        pw.close();
    }
    public static void main(String[] args) throws Exception {
        
        
        new Thread(null,new Runnable() {
            public void run() {
                new Main().solve();
            }
        },"1",1<<26).start();
        
        
    }
    static class trie{
        trie x,y;
        Integer z;
        trie(int z){
            x=null;
            y=null;
            this.z=z;
        }
        public String toSring() {
        	return (z+" ");
        }
    }
    static void debug(Object... o) {
        System.out.println(Arrays.deepToString(o));
        }
        
        static class InputReader 
        {
        private final InputStream stream;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;
        private SpaceCharFilter filter;
 
        public InputReader(InputStream stream) 
        {
            this.stream = stream;
        }
        public int snext() 
        {
            if (snumChars == -1)
                throw new InputMismatchException();
            if (curChar >= snumChars) 
            {
                curChar = 0;
                try 
                {
                    snumChars = stream.read(buf);
                } 
                catch (IOException e) 
                {
                    throw new InputMismatchException();
                }
                if (snumChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }
 
        public int nextInt() 
        {
            int c = snext();
            while (isSpaceChar(c)) 
            {
                c = snext();
            }
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = snext();
            }
            int res = 0;
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public long nextLong()
        {
            int c = snext();
            while (isSpaceChar(c)) 
            {
                c = snext();
            }
            int sgn = 1;
            if (c == '-') 
            {
                sgn = -1;
                c = snext();
            }
            long res = 0;
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public int[] nextIntArray(int n) 
        {
            int a[] = new int[n];
            for (int i = 0; i < n; i++) 
            {
                a[i] = nextInt();
            }
            return a;
        }
 
        public String readString()
        {
            int c = snext();
            while (isSpaceChar(c)) 
            {
                c = snext();
            }
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = snext();
            } while (!isSpaceChar(c));
            return res.toString();
        }
 
        public String nextLine() 
        {
            int c = snext();
            while (isSpaceChar(c))
                c = snext();
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = snext();
            } while (!isEndOfLine(c));
            return res.toString();
        }
 
        public boolean isSpaceChar(int c) 
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
 
        private boolean isEndOfLine(int c) 
        {
            return c == '\n' || c == '\r' || c == -1;
        }
 
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
        public static long mod = 1000000007;
        public static int d;
        public static int p;
        public static int q;
        public void extended(int a,int b) {
            if(b==0) {
                d=a;
                p=1;
                q=0;
            }
            else
            {
                extended(b,a%b);
                int temp=p;
                p=q;
                q=temp-(a/b)*q;
            }
        }
        public static int binaryExponentiation(int x,int n)
        {
            int result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=result * x;
                x=x*x;
                n=n/2;
            }
            return result;
        }
        
        public static long binaryExponentiation(long x,long n)
        {
            long result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=result * x;
                x=x*x;
                n=n/2;
            }
            return result;
        }
        
        public static int modularExponentiation(int x,int n,int M)
        {
            int result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=(result * x)%M;
                x=(x%M*x)%M;
                n=n/2;
            }
            return result;
        }
        
        public static long modularExponentiation(long x,long n,long M)
        {
            long result=1;
            while(n>0)
            {
                if(n % 2 ==1)
                    result=(result%M * x%M)%M;
                x=(x%M * x%M)%M;
                n=n/2;
            }
            return result;
        }
        
        public static long modInverse(int A,int M)
        {
            return modularExponentiation(A,M-2,M);
        }
        
        public static long modInverse(long A,long M)
        {
            return modularExponentiation(A,M-2,M);
        }
        public static long[] shuffle(long[] a,Random gen)
        {
            int n = a.length;
            for(int i=0;i<n;i++)
            {
                int ind = gen.nextInt(n-i)+i;
                long temp = a[ind];
                a[ind] = a[i];
                a[i] = temp;
            }
            return a;
        }
        
        public static void swap(int a, int b){
            int temp = a;
            a = b;
            b = temp;
        }
        
        public static HashSet<Integer> primeFactorization(int n)
        {
            HashSet<Integer> a =new HashSet<Integer>();
            for(int i=2;i*i<=n;i++)
            {
                while(n%i==0)
                {
                    a.add(i);
                    n/=i;
                }
            }
            if(n!=1)
                a.add(n);
            return a;
        }
        
        public static void sieve(boolean[] isPrime,int n)
        {
            for(int i=1;i<n;i++)
                isPrime[i] = true;
            
            isPrime[0] = false;
            isPrime[1] = false;
            
            for(int i=2;i*i<n;i++)
            {
                if(isPrime[i] == true)
                {
                    for(int j=(2*i);j<n;j+=i)
                        isPrime[j] = false;
                }
            }
        }
        
        public static long GCD(long gcd,long x)
        {
            if(x==0)
                return gcd;
            else
                return GCD(x,gcd%x);
        }
        
        static class pair implements Comparable<pair>
        {
            Integer x;
            Integer y,z;
            Long val;
            pair(int x,int y,int z,long val)
            {
                this.x=x;
                this.y=y;
                this.z=z;
                this.val=val;
            }

            public int compareTo(pair o) {
                int result = x.compareTo(o.x);
                if(result==0)
                    result = y.compareTo(o.y);
                
                return result;
            }  
            
            public String toString()
            {
                return x+" "+y;
            }
            
            public boolean equals(Object o)
            {
                if (o instanceof pair)
                {
                    pair p = (pair)o;
                    return p.x == x && p.y == y ;
                }
                return false;
            }
            
            public int hashCode()
            {
                return new Double(x).hashCode()*31 + new Long(y).hashCode();
            }
        }
        
    
}

class dsu{
    int parent[];
    dsu(int n){
        parent=new int[n+1];
        for(int i=0;i<=n;i++)
        {
            parent[i]=i;
        }
    }
    int root(int n) {
        while(parent[n]!=n)
        { 
            parent[n]=parent[parent[n]];
            n=parent[n];
        }
        return n;
    }
    void union(int _a,int _b) {
        int p_a=root(_a);
        int p_b=root(_b);
        
            parent[p_a]=p_b;
        
            
    }
    boolean find(int a,int b) {
        if(root(a)==root(b))
            return true;
        else
            return  false;
    }
    
    
}
class Segment{ 
    int seg[]; 
    int a[];
    int lazy[];
    Segment (int n,int b[]){
        seg=new int[4*n];
        lazy=new int[4*n];
        a=new int[b.length];
        a=b.clone();
    }
    public void build(int node,int start,int end) {
        if(start==end) {
            seg[node]=a[start];
            return ;
        }
        int mid=(start+end)/2;
        build(2*node+1,start,mid);
        build(2*node+2,mid+1,end);
        seg[node]=seg[2*node+1]+seg[2*node+2];
    }
    public void update(int node,int start,int end,int id,int val) {
        if(start==end) {
            seg[node]=a[start]=val;
            return;
        }
        int mid=(start+end)/2;
        if(id>=start && id<=mid) {
            update(2*node+1,start,mid,id,val);
        }
        else
            update(2*node+2,mid+1,end,id,val);
        seg[node]=seg[2*node+1]+seg[2*node+2];
    }
    public int query(int node,int start,int end,int l,int r) {
        if(l>end || r<start)
            return 0;
        if(start>=l && end<=r)
            return seg[node];
        
        int  mid=(start+end)/2;
        return (query(2*node+1,start,mid,l,r)+query(2*node+2,mid+1,end,l,r));
    }
    public void updateRange(int node,int start,int end,int l,int r,int val) {
        if(lazy[node]!=0) {
            if(start!=end) {
                lazy[2*node+1]+=lazy[node];
                lazy[2*node+2]+=lazy[node];
            }
            lazy[node]=0;
        }
        if(l>end || r<start)
            return ;
        if(start>=l && end<=r) {
            seg[node]=(end-start+1)*val;
            if(start!=end) {
                lazy[2*node+1]+=val;
                lazy[2*node+2]+=val;
            }
            lazy[node]=0;
            return ;
        }
        int mid=(start+end)/2;
        updateRange(2*node+1,start,mid,l,r,val);
        updateRange(2*node+2,mid+1,end,l,r,val);
        seg[node]=seg[2*node+1]+seg[2*node+2];
    }
    public int queryRange(int node,int start,int end,int l,int r) {
        if(l>end || r<start)
            return 0;
        if(lazy[node]!=0) {
            seg[node]=(end-start+1)*lazy[node];
            if(start!=end) {
                lazy[2*node+1]+=lazy[node];
                lazy[2*node+2]+=lazy[node];
            }
            lazy[node]=0;
        }
        if(start>=l && end<=r)
            return seg[node];
        
        int  mid=(start+end)/2;
        return (query(2*node+1,start,mid,l,r)+query(2*node+2,mid+1,end,l,r));
    }
    
}
