#include <iostream>
#include <cstring>
using namespace std;

int min(int a, int b, int c){
    if (a <= b && a <= c){
        return a;
    }
    if (b <= a && b <= c){
        return b;
    }
    if (c <= a &&  c <= b){
        return c;
    }
}

int main() {
    char string_1[1001];
    char string_2[1001];
    cin >> string_1 >> string_2;
    int length_1 = strlen(string_1), length_2 = strlen(string_2);
    int** arr = new int*[length_1 + 1];
    for (int i = 0; i <= length_1; ++i){
        arr[i] = new int[length_2 + 1];
    }
    for (int i = 0; i <= length_1; ++i){
        for (int j = 0; j <= length_2; ++j){
            if(i == 0 && j == 0){
                arr[i][j] = 0;
                continue;
            }
            if (j == 0 && i != 0){
                arr[i][j] = i;
                continue;
            }
            if (i == 0 && j != 0){
                arr[i][j] = j;
                continue;
            }
            if (string_1[i - 1] == string_2[j - 1]){
                arr[i][j] = arr[i - 1][j - 1];
                continue;
            }
            arr[i][j] = min(arr[i][j - 1] + 1, arr[i - 1][j] + 1, arr[i - 1][j - 1] + 1);
        }
    }
    /*
    for (int i = 0; i <= length_1; ++i){
        for (int j = 0; j <= length_2; ++j){
            cout << arr[i][j] << " ";
            if (j == length_2)
                cout << "\n";
        }
    }
     */
    cout << arr[length_1][length_2] << "\n";
    /*
    cout << length_1 << "\n" << length_2;
     */
}