#include <bits/stdc++.h>

using ll = long long;
using namespace std;

using P = complex<double>;

double check(P a, P b, P c) {
	//cout << abs(abs(a - (b+c)/2.0) - abs((b-c)/2.0)) << '\n';
	return abs(abs(a - (b+c)/2.0) - abs((b-c)/2.0));
}

void solve() {
	complex<double> a, b, c;

	double x, y;
	cin >> x >> y;
	a = complex<double>(x, y);
	cin >> x >> y;
	b = complex<double>(x, y);
	cin >> x >> y;
	c = complex<double>(x, y);
	double res = 10000.0;
	res = min(res, check(a, b, c));
	res = min(res, check(b, c, a));
	res = min(res, check(c, a, b));

	cout << res << "\n";
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout << setprecision(10);

	solve();
}