#include<bits/stdc++.h>
using namespace std;
int main(){ 
	double a;
    int n;
    cin>>n;
    a=(n+n/100+n%100)/3.0;
	printf("%.3f",a);
	
}


/**************************************************************
	Problem: 1618
	User: zhuangsongyu
	Language: C++
	Result: Wrong Answer
****************************************************************/