#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
string str;
string str1;
cin >> str >> str1;
int n = str.length();
int m = str1.length();
int i = 0, j = 0;
vector<vector<int>> dp(n + 1, vector<int> (m + 1, 0));
for (i = 0; i <= n; i++) {
dp[i][0] = i;
}
for (j = 0; j <= m; j++) {
dp[0][j] = j;
}
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
if (str[i] == str1[j]) {
dp[i + 1][j + 1] = dp[i][j];
}
else {
dp[i + 1][j + 1] = min(dp[i + 1][j] + 1, min(dp[i][j + 1] + 1, dp[i][j] + 1));
}
}
}
cout << dp[n][m] << endl;
return 0;
}