#include<bits/stdc++.h>
using namespace std;
int main()
{
    double n,ans;
    cin>>n;
    ans=1*n/23;
    ans=int(ans*100000000+0.5);
    ans/=100000000;
    printf("%.8f",ans);
	return 0;
}

是精度不够吗？80分，怎么回事呀？