杭电OJ2011

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
int main()
{
	int m, n,p;
	while (cin >> m)
	{
		p = m;
		while (p--)
		{
			cin >> n;
			int t;
			double s = 0, i;
			for (i = 1; i <= n; i++)
			{
				t = pow(-1, i - 1);
				s = s + (1 / i)*t;
			}
			cout << setprecision(2) << fixed << s << endl;
		}
	}
}