//http://acm.hdu.edu.cn/showproblem.php?pid=2011
#include <cstdio>
#include <cmath>
int main(){
int m,n;
double sum;
scanf("%d",&m);
for(int i=0;i<m;i++){
scanf("%d",&n);
sum=0.0;
for(int j=1;j<=n;j++){
sum+=1.0/(double)j*pow(-1,j-1);
}
printf("%.2f\n",sum);
return 0;