#include <bits/stdc++.h>
using namespace std;
int x,y;
int main(){
    cin>>x>>y;
    cout<<(y/x)*5;
	return 0;
}
/**************************************************************
	Problem: 1417
	User: zengdongxin
	Language: C++
	Result: Accepted
	Time:19 ms
	Memory:2072 kb
****************************************************************/