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

int main()
{
    ios_base::sync_with_stdio(0);
    int mat[4][4] = {{0, 10, 15, 20},
                    {10, 0, 35, 25},
                    {15, 35, 0 ,30},
                    {20, 25, 30, 0}
    };
    int arr[] = {0, 1, 2, 3};
    int min_cost = 2e9;
    do {
        int cost = 0;
        for(int i = 0; i < 3; i++) {
            cost += mat[arr[i]][arr[i + 1]];
        }
        cost += mat[arr[3]][arr[0]];
        min_cost = min(min_cost, cost);

    } while(next_permutation(arr, arr + 4));
    cout << min_cost << endl;
    return 0;
}