#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;




int main() {
	
	
	double a,b,x;//long long int x;
	cin>>a>>b;
	
	x=50*a+((50*a)/(0.8+0.2*b));
	cout<<(int)x<<endl;

	return 0;
}