#include<bits/stdc++.h>
using namespace std;
int main(){
    float j,i,n;
    int x;
    cin>>x;
    j=x%100;
    i=x/100;
    n=(i+j+x)/3.0;
    printf("%.2f",n);
}
/**************************************************************
	Problem: 1619
	User: huanglingkai
	Language: C++
	Result: Wrong Answer
****************************************************************/