#include<bits/stdc++.h>
using namespace std;
int a,b,c;
int main(){
    float d;
    cin>>a;
    b=a/100;
    c=a%100;
    d=(a+b+c)/3.0;
    printf("%.2f",d); 
    return 0;
}
/**************************************************************
	Problem: 1618
	User: chenyichuen
	Language: C++
	Result: Accepted
	Time:18 ms
	Memory:2072 kb
****************************************************************/