#include <iostream>
#include <thread>
#include <vector>
#include <mutex>
#include <ctime>
#include <set>
#include <algorithm>
#include <string>
#include <cmath>

using namespace std;

int main() {
	string fir;
	cin >> fir;
	string sec;
	cin >> sec;

	int n = fir.size(), m = sec.size();
	vector<vector<int>> dp(n + 1, vector<int>(m + 1));

	for (int i = 0; i < n + 1; i++)
		dp[i][0] = i;
	for (int i = 0; i < m + 1; i++)
		dp[0][i] = i;
	for (int i = 1; i < n + 1; i++) {
		for (int j = 1; j < m + 1; j++) {
			if (fir[i - 1] == sec[j - 1])
				dp[i][j] = dp[i - 1][j - 1];
			else
				dp[i][j] = min(min(dp[i - 1][j] + 1, dp[i][j - 1] + 1), dp[i - 1][j - 1] + 1);
		}
	}
	cout << dp[n][m];

	return 0;
}