#include<stdio.h>
int main()
{
int n;
printf("# Cards Overhang\n");
while(scanf("%d",&n)!=EOF)
double sum=0.5;
int i;
for(i=2;i<=n;i++)
sum+=1.0/(2*i);
printf("%5d %.3lf\n",n,sum);
}
return 0;