#include <iostream>
#include <cstdlib>
#include <cmath>
 
using namespace std;
 
int main()
{
	int n;
	double x1, y1, r1, x2, y2, r2;
	double d,l;
	cin >> n;
	cout.setf(ios::fixed);
	cout.precision(2);
	for (int i = 0; i < n; i++)
	{
		cin >> x1; cin >> y1; cin >> r1;
		cin >> x2; cin >> y2; cin >> r2;
		d = sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2));
		 if (r1 + r2 <= d) //okregi rozlaczne/styczne
			l = 0;
		else if (d > abs(r1 - r2) && d < r1 + r2)//okregi przecinaja sie
			l = r1 + r2 - d;
		else if (d <= abs(r1 - r2)) //jeden w drugim
		{
			if (r1 < r2)
				l = 2 * r1;
			else
				l = 2 * r2;
		}
			cout << l << endl;
	}
    return 0;
}

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MQotMTAwMDAgLTEwMDAwIDEwMDAwMDAKMTAwMDAgMTAwMDAgMTAwMDAwMA==

1
-10000 -10000 1000000
10000 10000 1000000