#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
const int INF = 1e9;
const int maxn = 5005;
string A, B;
int dp[maxn][maxn];
int rec(int i, int j) {
    if(i < 0) {
        return j + 1;
    }
    if(j < 0) {
        return i + 1;
    }
    if(dp[i][j] != -1) {
        return dp[i][j];
    }
    int res = INF;

    if(A[i] == B[j]) {
        res = min(res, rec(i - 1, j - 1));
    }

    res = min(res, rec(i - 1, j) + 1);
    res = min(res, rec(i, j - 1) + 1);
    res = min(res, rec(i - 1, j - 1) + 1);

    dp[i][j] = res;
    return res;
}
int main() {
    for(int i = 0; i < maxn; i++) {
        for(int j = 0; j < maxn; j++) {
            dp[i][j] = -1;
        }
    }
    cin >> A >> B;

    cout << rec(A.size() - 1, B.size() - 1) << endl;
    return 0;
}