#include <bits/stdc++.h>

using namespace std;
#define ll long long
#define ull unsigned long long
#define pb push_back
#define MAXN 1100
#define F first
#define S second

string s1, s2;
int dp[MAXN][MAXN];

int main () {
    ios_base::sync_with_stdio (false);
    cin.tie (nullptr); cout.tie (nullptr);
    // freopen ("input.txt", "r", stdin);
    // freopen ("output.txt", "w", stdout);
    cin >> s1 >> s2;
    for (int n = 0; n < s1.length() + 1; n++) {
        for (int m = 0; m < s2.length() + 1; m++) {
            if (n == 0 && m == 0) dp[n][m] = 0;
            else if (n == 0) dp[n][m] = m;
            else if (m == 0) dp[n][m] = n;
            else {
                int res1 = dp[n][m - 1] + 1;
                int res2 = dp[n - 1][m] + 1;
                int res3 = dp[n - 1][m - 1] + (s1[n - 1] == s2[m - 1] ? 0 : 1);
                int result = min(min(res1, res2), res3);
                dp[n][m] = result;
            }
        }
    }
    cout << dp[s1.length()][s2.length()];
    return 0;
}