// LCS com Bit-paralelo
//https://www.spoj.com/problems/LCS0/
#include <stdio.h>
#include <limits.h>
#include <stdlib.h>
#define INF INT_MAX

char A[50002], B[50002];

int main(){
    scanf("%s\n%s",A,B);
    register int i, j, k, m, n;
    for ( m = 0; A[m]; ++m) ;
    for ( n = 0; B[n]; ++n) ;
    if ( m == 0 || n == 0) return 0;
    char *X = A, *Y = B;
    if (m < n) {
        char *T;
        T = X ; X = Y ; Y = T ;
        k = m ; m = n ; n = k ;
    }

    int w =( m + 31) >> 5; // ceil [m /32]

    unsigned int S [256][ w ]; // Sigma {all char }
    for ( i = 0; i < 256; ++i)
    for ( j = 0; j < w ; ++j)
    S [ i ][ j ]=0;
    unsigned int set = 1;
    for ( i = 0 , j = 0; i < m ; ++i) {
        S [ X [ i ]][ j ] |= set ;
        set <<= 1;
        if (!set) { ++set; ++j;}
    }
    unsigned int L[w]; // Vetor L(i)
    unsigned int b1 , b2 , c ; // borrows and carries
    for ( i = 0; i < w ; ++i) L[i] = 0;
    register unsigned int U, V;
    for ( i =0; i < n ; ++i) {
        b1 = 1; b2 = 0;
        for ( j = 0; j < w ; ++j) {
            U = L[j] | S [ Y[i] ][j];
            c = L[j] >> 31;
            V = U - ( L[j] << 1 | b1 + b2 ) ;
            b1 = c; b2 = ( V > U ) ;
            L[j] = U & (~V) ;
        }
    }
    for ( k = 0 , i = 0; i < w ; ++i)
        for (; L [ i ]; ++k) L[i] &= L[i] - 1;
    printf("%d\n", k);
 }