#include <stdio.h>#include <math.h>int n;void solve(){double ans=0;if (n<=100)for(int i=1;i<=n;i++) ans+=1.0/i;else ans=log(n)+0.57721566490153286060+1.0/2/n-1.0/12/n/n+1.0/120/n/n/n/n;printf("%.8fn",ans);}int main(){while(scanf("%d",&n)!=EOF){solve();}}
