#include <iostream>
#include <cmath>

using namespace std;

double d (pair<double, double> p1,pair<double, double> p2,pair<double, double> p3) {
    double ox = (p1.first + p1.second)/2, oy = (p2.first + p2.second)/2;
    double r = ((pow(p2.second - p1.second, 2) + pow(p2.first - p1.first, 2)))/4;

    double xp1 = sqrt(r/(pow(((p3.second - oy)/(p3.first - ox)), 2) + 1)) + ox;
    double xp2 = -sqrt(r/(pow(((p3.second - oy)/(p3.first - ox)), 2) + 1)) + ox;

    double yp1 = ((p3.second - oy)/(p3.first-ox))*(xp2-ox) + oy;
    double yp2 = ((p3.second - oy)/(p3.first-ox))*(xp1-ox) + oy;

    double d1 = sqrt(pow(p3.second - yp1, 2) + pow(p3.first - xp2, 2));
    double d2 = sqrt(pow(p3.second - yp2, 2) + pow(p3.first - xp1, 2));

    return min(d1, d2);
}

int main() {
    double x1, y1;
    double x2, y2;
    double x3, y3;
    cin >> x1 >> y1;
    cin >> x2 >> y2;
    cin >> x3 >> y3;

    double mind1 = d({x1, y1}, {x2, y2}, {x3, y3});
    double mind2 = d({x3, y3}, {x2, y2}, {x1, y1});
    double mind3 = d({x2, y2}, {x1, y1}, {x3, y3});
    double mind4 = d({x1, y1}, {x3, y3}, {x2, y2});
    double mind5 = d({x2, y2}, {x3, y3}, {x1, y1});
    double mind6 = d({x3, y3}, {x1, y1}, {x2, y2});

    double mind12 = min(mind1, mind2);
    double mind34 = min(mind3, mind4);
    double mind56 = min(mind5, mind6);

    double minDs = min(mind12, min(mind34, mind56));

    cout << minDs << "\n";

    return 0;
}