#include <iostream> using namespace std;

int main() { int a, b, c; cin >> a >> b >> c;

int total = 0;
if (a <= 5) {
    total += a * 20;
} else if (a <= 10) {
    total += a * 18;
} else {
    total += a * 15;
}

if (c == 0) {
    total += b * 20;
}

cout << total << endl;
return 0;

}