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 org.omg.CORBA.INTERNAL;

import javax.swing.plaf.basic.BasicTreeUI;
import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.*;


public class Main {
    private static Scanner sc;
    private static Printer pr;
    static boolean []visited;
    static int []color;
    static int []pow=new int[(int)3e5+1];
    static int []count;
    static boolean check=true;
    static boolean checkBip=true;
    static TreeSet<Integer>[]list;
    private static long aLong=(long)(Math.pow(10,9)+7);
    static final long div=998244353;
    static  int answer=0;
    static int[]countSubTree;
    static int[]colorNode;
    static boolean con=true;
    static ArrayList<Integer>dfsPath=new ArrayList<>();
    static ArrayList<Integer>ans=new ArrayList<>();
    static boolean[]rec;
    static int min=Integer.MAX_VALUE;
    static ArrayList<Task>tasks=new ArrayList<>();
    private static void solve() throws IOException {
        String s=sc.next();
        String t=sc.next();
        int []left=new int[t.length()];
        int []right=new int[t.length()];
        int posLeft=0;
        int posRight=t.length()-1;
        for (int i=0;i<s.length();++i){
            if (posLeft==t.length()) break;
            if (s.charAt(i)==t.charAt(posLeft)){
                //System.out.println("pos:"+posLeft+" i:"+i);
                left[posLeft]=i;
                ++posLeft;
            }
        }
        for (int i=s.length()-1;i>=0;--i){
            if (posRight==-1) break;
            if (s.charAt(i)==t.charAt(posRight)){
                //System.out.println("posr:"+posRight+" i:"+i);
                right[posRight]=i;
                --posRight;
            }
        }
        //System.out.println("left:"+Arrays.toString(left));
        //System.out.println("right:"+Arrays.toString(right));
        long ans=Math.max(right[0],s.length()-left[t.length()-1]-1);
        //System.out.println("ans:"+ans);
        for (int i=0;i<t.length()-1;++i) ans=Math.max(ans,right[i+1]-left[i]-1);
        pr.println(ans);
    }
    public static long power(long x,long y){
        if (y==0) return 1%aLong;
        long u=power(x,y/2);
        u=((u)*(u))%aLong;
        if (y%2==1) u=(u*(x%aLong))%aLong;
        return u;
    }
    public static class Task{
        int  deg;
        int xor;
        public Task(int   w,int v) {
            this.deg = w;
            this.xor=v;
        }
    }
    public static void printSolve(StringBuilder str, int[] colors, int n,int color){
        for(int i = 1;i<=n;++i)
            if(colors[i] == color)
                str.append(i + " ");
        str.append('\n');
    }
    public static class pairTask{
        int  val;
        int size;
        public pairTask(int   x, int  y) {
            this.val = x;
            this.size = y;
        }
    }
    public static void subTree(int src,int parent){
        countSubTree[src]=1;
        for (int v:list[src]){
            if (v==parent)
                continue;
            subTree(v,src);
            countSubTree[src]+=countSubTree[v];
        }
    }
    public static boolean prime(long src){
        for (int i=2;i*i<=src;i++){
            if (src%i==0)
                return false;
        }
        return true;
    }
    public static void bfsColor(int src){
        Queue<Integer>queue = new ArrayDeque<>();
        queue.add(src);
        while (!queue.isEmpty()){
            boolean b=false;
            int vertex=-1,p=-1;
            int poll=queue.remove();
            for (int v:list[poll]){
                if (color [v]==0){
                    vertex=v;
                    break;
                }
            }
            for (int v:list[poll]){
                if (color [v]!=0&&v!=vertex){
                    p=v;
                    break;
                }
            }
            for (int v:list[p]){
                if (color [v]!=0){
                    color[vertex]=color[v];
                    b=true;
                    break;
                }
            }
            if (!b){
                color[vertex]=color[poll]+1;
            }
        }
    }
    static int add(int a,int b ){
        if (a+b>=div)
            return (int)(a+b-div);
        return (int)a+b;
    }
    public static int isBipartite(ArrayList<Integer>[]list,int src){
        color[src]=0;
        Queue<Integer>queue=new LinkedList<>();
        int []ans={0,0};
        queue.add(src);
        while (!queue.isEmpty()){
            ans[color[src=queue.poll()]]++;
            for (int v:list[src]){
                if (color[v]==-1){
                    queue.add(v);
                    color[v]=color[src]^1;
                }else if (color[v]==color[src])
                    check=false;
            }
        }
        return add(pow[ans[0]],pow[ans[1]]);
    }
    public static int powerMod(long b, long e){
        long ans=1;
        while (e-->0){
            ans=ans*b%div;
        }
        return (int)ans;
    }
    public static int dfs(int s){
        int ans=1;
        visited[s]=true;
        for (int k:list[s]){
            if (!visited[k]){
                ans+=dfs(k);
            }
        }
        return ans;
    }
    public static int[] radixSort(int[] f) {
        int[] to = new int[f.length];
        {
            int[] b = new int[65537];
            for (int i = 0; i < f.length; i++) b[1 + (f[i] & 0xffff)]++;
            for (int i = 1; i <= 65536; i++) b[i] += b[i - 1];
            for (int i = 0; i < f.length; i++) to[b[f[i] & 0xffff]++] = f[i];
            int[] d = f;
            f = to;
            to = d;
        }
        {
            int[] b = new int[65537];
            for (int i = 0; i < f.length; i++) b[1 + (f[i] >>> 16)]++;
            for (int i = 1; i <= 65536; i++) b[i] += b[i - 1];
            for (int i = 0; i < f.length; i++) to[b[f[i] >>> 16]++] = f[i];
            int[] d = f;
            f = to;
            to = d;
        }
        return f;
    }
    public static long []primeFactor(int n){
        long []prime=new long[n+1];
        prime[1]=1;
        for (int i=2;i<=n;i++)
            prime[i]=((i&1)==0)?2:i;
        for (int i=3;i*i<=n;i++){
            if (prime[i]==i){
                for (int j=i*i;j<=n;j+=i){
                    if (prime[j]==j)
                        prime[j]=i;
                }
            }
        }
        return prime;
    }
    public static StringBuilder binaryradix(long number){
        StringBuilder builder=new StringBuilder();
        long remainder;
        while (number!=0) {
            remainder = number % 2;
            number >>= 1;
            builder.append(remainder);
        }
        builder.reverse();
        return builder;
    }
    public static int binarySearch(long[] a, int index,long target) {
            int l = index;
            int h = a.length - 1;
            while (l<=h) {
                int med = l + (h-l)/2;
                if(a[med] - target <= target) {
                    l = med + 1;
                }
                else h = med  - 1;
            }
            return h;
    }
    public static int val(char c){
        return c-'0';
    }
    public static long gcd(long a,long b) {
        if (a == 0) return b;
        return gcd(b % a, a);
    }
        private static class Pair implements Comparable<Pair> {
            long x;
            long y;

            Pair() {
                this.x = 0;
                this.y = 0;
            }

            Pair(long x, long y) {
                this.x = x;
                this.y = y;
            }

            @Override
            public boolean equals(Object obj) {
                if (this == obj) {
                    return true;
                }
                if (obj == null) return false;
                Pair other = (Pair) obj;
                if (this.x == other.x && this.y == other.y) {
                    return true;
                }
                return false;
            }

            @Override
            public int compareTo(Pair other) {
                if (this.x != other.x) return Long.compare(this.x, other.x);
                return Long.compare(this.y*other.x, this.x*other.y);
            }
    }

    public static void main(String[] args) throws IOException {
        sc = new Scanner(System.in);
        pr = new Printer(System.out);
        solve();

        pr.close();
       // sc.close();
    }
    private static class Scanner {
        BufferedReader br;

        Scanner (InputStream in) {
            br = new BufferedReader(new InputStreamReader(in));
        }

        private boolean isPrintable(int ch) {
            return ch >= '!' && ch <= '~';
        }

        private boolean isCRLF(int ch) {
            return ch == '\n' || ch == '\r' || ch == -1;
        }

        private int nextPrintable() {
            try {
                int ch;
                while (!isPrintable(ch = br.read())) {
                    if (ch == -1) {
                        throw new NoSuchElementException();
                    }
                }

                return ch;
            } catch (IOException e) {
                throw new NoSuchElementException();
            }
        }

        String next() {
            try {
                int ch = nextPrintable();
                StringBuilder sb = new StringBuilder();
                do {
                    sb.appendCodePoint(ch);
                } while (isPrintable(ch = br.read()));

                return sb.toString();
            } catch (IOException e) {
                throw new NoSuchElementException();
            }
        }

        int nextInt() {
            try {
                // parseInt from Integer.parseInt()
                boolean negative = false;
                int res = 0;
                int limit = -Integer.MAX_VALUE;
                int radix = 10;

                int fc = nextPrintable();
                if (fc < '0') {
                    if (fc == '-') {
                        negative = true;
                        limit = Integer.MIN_VALUE;
                    } else if (fc != '+') {
                        throw new NumberFormatException();
                    }
                    fc = br.read();
                }
                int multmin = limit / radix;

                int ch = fc;
                do {
                    int digit = ch - '0';
                    if (digit < 0 || digit >= radix) {
                        throw new NumberFormatException();
                    }
                    if (res < multmin) {
                        throw new NumberFormatException();
                    }
                    res *= radix;
                    if (res < limit + digit) {
                        throw new NumberFormatException();
                    }
                    res -= digit;

                } while (isPrintable(ch = br.read()));

                return negative ? res : -res;
            } catch (IOException e) {
                throw new NoSuchElementException();
            }
        }

        long nextLong() {
            try {
                // parseLong from Long.parseLong()
                boolean negative = false;
                long res = 0;
                long limit = -Long.MAX_VALUE;
                int radix = 10;

                int fc = nextPrintable();
                if (fc < '0') {
                    if (fc == '-') {
                        negative = true;
                        limit = Long.MIN_VALUE;
                    } else if (fc != '+') {
                        throw new NumberFormatException();
                    }
                    fc = br.read();
                }
                long multmin = limit / radix;

                int ch = fc;
                do {
                    int digit = ch - '0';
                    if (digit < 0 || digit >= radix) {
                        throw new NumberFormatException();
                    }
                    if (res < multmin) {
                        throw new NumberFormatException();
                    }
                    res *= radix;
                    if (res < limit + digit) {
                        throw new NumberFormatException();
                    }
                    res -= digit;

                } while (isPrintable(ch = br.read()));

                return negative ? res : -res;
            } catch (IOException e) {
                throw new NoSuchElementException();
            }
        }

        float nextFloat() {
            return Float.parseFloat(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            try {
                int ch;
                while (isCRLF(ch = br.read())) {
                    if (ch == -1) {
                        throw new NoSuchElementException();
                    }
                }
                StringBuilder sb = new StringBuilder();
                do {
                    sb.appendCodePoint(ch);
                } while (!isCRLF(ch = br.read()));

                return sb.toString();
            } catch (IOException e) {
                throw new NoSuchElementException();
            }
        }

        void close() {
            try {
                br.close();
            } catch (IOException e) {
//				throw new NoSuchElementException();
            }
        }
    }
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 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();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

    }

    static class List {
        String Word;
        int length;

        List(String Word, int length) {
            this.Word = Word;
            this.length = length;
        }
    }
    private static class Printer extends PrintWriter {
        Printer(PrintStream out) {
            super(out);
        }
    }
}