#include <iostream>
#include <cstring>
#include <vector>
#include <set>
using namespace std;
string A, B;
int dp[1005][1005];
int rec(int i, int j) {
    if(i == -1 and j == -1) {
        return 0;
    }
    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(A[i] == B[j]) {
        result = min(result, rec(i - 1, j - 1) + 1);
    }
    result = min(result, rec(i - 1, j) + 1);
    result = min(result, rec(i, j - 1) + 1);
    return dp[i][j] = result;
}

int combinations(int i, int j) {
    
}
int main()
{
    cin >> A >> B;
    memset(dp, -1, sizeof dp);
    
    cout << rec((int) A.size() - 1, (int) B.size() - 1) << endl;;

    return 0;
}
/*
ABB
BA
 
 **/