#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m=0;
	float x=0,y=0,h=0;
	cin>>n;
	y=n%100;
	x=n/100;
	h=(n+x+y)/3.0;
	printf("%.2f",h);
}
/**************************************************************
	Problem: 1618
	User: huxuanchen
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/