#include <iostream>
using namespace std;

int n, x;
double y;

int main()
{
	cin >> n;
	while (cin >> x)
	{
		if (x >= 0 && x < 2) y = -x + 2.5;
		else if (x >= 2 && x < 4) y = 2 - 1.5 * (x - 3) * (x - 3);
		else y = (double)x / 2 - 1.5;
		printf("y=%.1f\n", y);
	}
	return 0;
}