#include <bits/stdc++.h>
#include <cmath>

#include <iomanip>
#include <algorithm>
using namespace std;

class vec2 {
    public:
    vec2(long double x, long double y) : x(x), y(y) {}
    vec2 operator+(const vec2& v2) const {
        return {x+v2.x, y+v2.y};
    }
    vec2 operator-(const vec2& v2) const {
        return {x-v2.x, y-v2.y};
    }
    friend vec2 operator*(long double r, const vec2& v2) {
        return {r*v2.x, r*v2.y};
    }
    long double norm() const {
        return sqrt(x*x + y*y);
    }
    vec2 normalize() const {
        return (1/(norm()))*(*this);
    }
    private:
        long double x, y;
};

long double diff(vec2 A, vec2 B, vec2 C) {
    vec2 AB = (0.5*(B-A));
    long double r = (AB).norm();
    vec2 S = A + AB;
    vec2 N = r*((C-S).normalize())+S;
    return (C-N).norm();
}

int main() {
    long double Ax, Ay, Bx, By, Cx, Cy;
    cin >> Ax >> Ay >> Bx >> By >> Cx >> Cy;
    vec2 A(Ax, Ay);
    vec2 B(Bx, By);
    vec2 C(Cx, Cy);

    long double res;
     res = diff(A, B, C);
     res = min(res, diff(B, A, C));
     res = min(res, diff(C, A, B));
     res = min(res, diff(C, B, A));
     res = min(res, diff(A, C, B));
     res = min(res, diff(B, C, A));
     cout <<setprecision(10)<< res << endl;

}


// double diff(double Ax, double Ay, double Bx, double By, double Cx, double Cy) {
//     double Sx = (Ax + Bx) / 2;
//     double Sy = (Ay + By) / 2;
//     double R2 = ((Ax - Bx) * (Ax - Bx) + (Ay - By) * (Ay - By)) / 4;
//     //cout << "R2 " << R2 << endl;
//     Cx -= Sx;
//     Cy -= Sy;
//     double x = sqrt(R2 / (1 + (Cy/Cx)*(Cy/Cx)));
//     double y = (Cy/Cx)*x;
//     //cout << "C " << Cx << " " << Cy << endl;
//     //cout << "xy " << x << " " << y << endl;
//     return min(sqrt((Cx-x)*(Cx-x) + (Cy-y)*(Cy-y)), sqrt((Cx+x)*(Cx+x) + (Cy+y)*(Cy+y)));
// }

// int main() {
//     double Ax, Ay, Bx, By, Cx, Cy;
//     cin >> Ax >> Ay >> Bx >> By >> Cx >> Cy;
//     //cout << diff(Ax, Ay, Bx, By, Cx, Cy) << ", " << diff(Ax, Ay, Cx, Cy, Bx, By) << ", " << diff(Bx, By, Cx, Cy, Ax, Ay) << endl;
//     double res = diff(Ax, Ay, Bx, By, Cx, Cy);
//     res = min(res, diff(Ax, Ay, Cx, Cy, Bx, By));
//     res = min(res, diff(Bx, By, Cx, Cy, Ax, Ay));
//     cout <<setprecision(10)<< res << endl;
// }