#include<bits/stdc++.h>
using namespace std;
int main(){
	long long n,x,sum=0,r1,r2;
	cin>>x>>n;
	r1=n/7;
	r2=n%7;
	sum=5*r1;
		if(x==7||x+r2==7){
			r2=r2-1;
		}
		else if(x+r2>7){
			r2=r2-2;
		}
		sum=sum+r2;
		cout<<sum*250;
	return 0;
}