#include <cstdio>

 #include <cstring>

 int n, m;

 int f[][];

 char s1[], s2[];

 inline int min(int x, int y)

 {

     return x < y ? x : y;

 }

 int main()

 {

     int i, j;

     scanf("%s %s", s1 + , s2 + );

     n = strlen(s1 + );

     m = strlen(s2 + );

     for(i = ; i <= n; i++) f[i][] = i;

     for(i = ; i <= m; i++) f[][i] = i;

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

         for(j = ; j <= m; j++)

         {

             if(s1[i] == s2[j]) f[i][j] = f[i - ][j - ];

             else f[i][j] = min(min(f[i - ][j], f[i][j - ]), f[i - ][j - ]) + ;

         }

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

     return ;

 }