#include <iostream>
#include <vector>
#include <cstring>
using namespace std;
string s1, s2;
int dp[5005][5005];
int rec(int i, int j) {
    if(i == -1) {
        return j + 1;
    }
    if(j == -1) {
        return i + 1;
    }
    if(dp[i][j] != -1) {
        return dp[i][j];
    }
    int result = 2e9;
    if(s1[i] == s2[j]) {
        result = min(result, rec(i - 1, j - 1));
    }
    result = min(result, rec(i - 1, j) + 1);
    result = min(result, rec(i, j - 1) + 1);
    result = min(result, rec(i - 1, j - 1) + 1);
    return dp[i][j] = result;
}
int main() {
    cin >> s1 >> s2;
    memset(dp, -1, sizeof dp);
    cout << rec(s1.size() - 1, s2.size() - 1) << endl;
    return 0;
}