#include<bits/stdc++.h>
using namespace std;
int main() {
	float a,g;
	int b,s;
	scanf("%d",&s);
	a=s/100;
	b=s%100;
	g=(s+a+b)/3.0;
	printf("%.2f",g);
    return 0;
}

/**************************************************************
	Problem: 1618
	User: huangcanwu
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/