#include<iostream>
using namespace std;
int main() {
    long long x, n;
    cin >> x >> n;
    if (n <= 7) {
        cout << 250 * (n % 7) << endl;
    }
    else {
        cout << 250 * (5 * (n / 7) + n % 7);
    }
    return 0;
}