#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: linyuhang
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/