#include <fstream>

#include <cstring>

using namespace std;

const int MAXN(1001);

int n, m, k, f[MAXN][MAXN];

char s[MAXN], t[MAXN];

main()

{

 ifstream a("edita.in");

 ofstream o("edita.out");

 a >> s;

 n = strlen(s);

 a >> t;

 m = strlen(t);

 for (int i = 1; i <= n; i++)

 f[i][0] = i;

 for (int i = 1; i <= m; i++)

 f[0][i] = i;

 for (int i = 1; i <= n; i++)

 for(int j = 1; j <= m; j++)

 f[i][j]=min(min(f[i-1][j],f[i][j-1])+1,f[i-1][j-1]+(int)(s[i-1]!=t[j-1]));

 o << f[n][m];

}