#include <bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c;
	float d;
	cin>>a;
	b=a/100;
	c=a%100;
	d=(a+b+c)/3.0;
	printf("%.2f",d);
	return 0;
}
/**************************************************************
	Problem: 1618
	User: panyuchen
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/