#include<cstdio>
#include <iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<vector>
#include<functional>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<numeric>

#define mod 1000000007;

using namespace std;
typedef long long ll;
typedef pair<ll, ll> Pr;

int A, B;

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