#include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <algorithm>

 using namespace std;

 const int maxn =  + ;

 int n;

 char s1[maxn], s2[maxn];

 int d[maxn][maxn], a[maxn];

 int main()

 {

     while(scanf("%s%s", s1 + , s2 + ) == )

     {

         n = strlen(s1 + );

         for(int i = ; i <= n; i++) d[i][i] = ;

         for(int l = ; l <= n; l++)

             for(int i = ; i + l -  <= n; i++)

             {

                 int j = i + l - ;

                 d[i][j] = d[i + ][j] + ;

                 for(int k = i + ; k <= j; k++) if(s2[i] == s2[k])

                     d[i][j] = min(d[i][j], d[i+][k-] + d[k][j]);

             }

         if(s1[] == s2[]) a[] = ; else a[] = ;

         for(int i = ; i <= n; i++)

         {

             a[i] = d[][i];

             if(s1[i] == s2[i]) a[i] = a[i - ];

             else

             {

                 for(int j = ; j < i; j++) a[i] = min(a[i], a[j] + d[j+][i]);

             }

         }

         printf("%d\n", a[n]);

     }

     return ;

 }