#include<cstdio>

 #include<cstring>

 #include<algorithm>

 using namespace std;

 const int N = ;

 char a[N], b[N];

 int dp[N][N];//dp[i][j]:a串的前i个字符转化成b串的前j个字符的最少操作数

 int main(){

     int i, j;

     scanf("%s%s", a+, b+);

     int alen = strlen(a+);

     int blen = strlen(b+);

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

         dp[i][] = i;

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

         dp[][j] = j;

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

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

             dp[i][j] = min(dp[i-][j-] + (a[i]!=b[j]), min(dp[i-][j]+, dp[i][j-]+));

     printf("%d\n", dp[alen][blen]);

     return ;

 }