#include<bits/stdc++.h>
using namespace std;
int main(){
	int x,a,b;
	cin>>x;
	a=x%100;
	b=x/100;
	printf("%.2f",(x+a+b)/3.0);
}
/**************************************************************
	Problem: 1618
	User: baizhoudeyueguang
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/