#include<iostream>
using namespace std;
int main(){
    int x,n,t,a;
    cin>>x>>n;
    t=n/7;
    if(n<7-x){
        cout<<n*250;
    }
    else if((n-x)%7==6) cout<<(n-(t*2)-1)*250;
    else{

        cout<<(n-(t*2))*250;
    }
    return 0;
}