#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	cout<<fixed<<setprecision(2)<<(n+n/100+n%100)/3.0;
}

/**************************************************************
	Problem: 1618
	User: admin
	Language: C++
	Result: Accepted
	Time:17 ms
	Memory:2072 kb
****************************************************************/