#include "stdio.h"
int main()
{
int n,m,i,j,s=-1;
float sum=0;
while(scanf("%d",&m)!=EOF)
{
for( i=1; i<=m; i++ )
{
scanf("%d",&n);
for( j=1; j<=n; j++ )
{
sum=0;
s*=-1;
sum+=(float)s*1/j;
}
printf("%.2f\n",sum);
}
}
}