#include <bits/stdc++.h>

using namespace std;

const int N = 2010;
int f[N][N];

char a[N], b[N];
int al, bl;
/*
测试用例：
abcd
ebde

答案：3
*/
int dfs(int i, int j) {
    if (i == 0) return j;
    if (j == 0) return i;

    if (~f[i][j]) return f[i][j];
    
    //增加、删除
    f[i][j] = min(dfs(i - 1, j) + 1, dfs(i, j - 1) + 1);

    //修改
    if (a[i] == b[j])
        return f[i][j] = min(f[i][j], dfs(i - 1, j - 1));
    else
        return f[i][j] = min(f[i][j], dfs(i - 1, j - 1) + 1);
}

int main() {
    memset(f, -1, sizeof f);
    cin >> a + 1 >> b + 1;
    al = strlen(a + 1), bl = strlen(b + 1);
    printf("%d\n", dfs(al, bl));
    return 0;
}