#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,swim,x,weekend;
	cin>>x>>n;
	if(x<=5)
		n-=2;
	else
		n-=x-5;
	weekend=n/7;
	if(n%7>5)
		weekend+=n%7-5;
	n-=weekend;
	cout<<n*250;
	return 0;
}