#include<bits/stdc++.h>
using namespace std;
 int main(){
 	int x,y,s;
 	cin>>x>>y;
 	s=(y/x)*5;
 	cout<<s;
 	return 0;
 } 
/**************************************************************
	Problem: 1417
	User: binzicheng1
	Language: C++
	Result: Accepted
	Time:17 ms
	Memory:2072 kb
****************************************************************/