#include<bits/stdc++.h> 
using namespace std;
int main()
{
	int y,x,h,t;
	cin>>x>>y;
	h=y/x;
	t=h*5;
	cout<<t;
}
/**************************************************************
	Problem: 1417
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/