#include<iostream>
#include<vector>
#include<string>
#include<cstring>
#include<algorithm>
#include<map>
#include<set>
#include<cmath>
#include<cassert>
#include<queue>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;

int main() {
	int A, B;
	cin >> A >> B;
	cout << (int)(50*A + (50*A/(0.8 + 0.2 * B))) << endl;
	return 0;
}