#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
using ll = long long;
using namespace std;
const int INF = 1e9;

int main() {
    int A, B;
    cin >> A >> B;

    cout << int(50 * A + (50 * A) / (0.8 + 0.2 * B)) << endl;

    return 0;
}