#include  <bits/stdc++.h>


using namespace std;

double dist(double ax, double ay, double bx, double by) {
    return hypot(ax-bx, ay-by);
}


double checkRight(double ax, double ay, double bx, double by, double cx, double cy) {
    double avgx = (ax+bx)/2;
    double avgy = (ay+by)/2;
    double l =  dist(avgx, avgy, ax, ay);
    double l2 = dist(avgx, avgy, cx, cy);
    return abs(l-l2);
}


double getT(double ax, double ay, double bx, double by, double cx, double cy) {
    return ((by-ay)*(bx-cx)-(bx-ax)*(by-cy))/((bx-cx)*(bx-cx)-(cy-by)*(by-cy));
}

double check(double ax, double ay, double bx, double by, double cx, double cy) {
    double t = getT( ax, ay, bx, by, cx, cy);
    double a2x = t*(cy - by) + ax;
    double a2y = t*(bx-cx) + ay;


    return min(dist(a2x, a2y, bx, by), dist(a2x, a2y, cx, cy));

}






int main() {
    vector<double> coords(6);
    for(auto&a:coords)cin>>a;

    double result = 200000;
    
    for(int i = 0; i < 6 ; i+=2){
        for(int j = 0; j < 6 ; j+=2){
            if(i == j) continue;
            for(int k = 0; k < 6 ; k+=2) {
                if(j==k||i==k) continue;
                //result = min(result, check(coords[i], coords[i+1], coords[j], coords[j+1], coords[k], coords[k+1]));
                result = min(result, checkRight(coords[i], coords[i+1], coords[j], coords[j+1], coords[k], coords[k+1]));
            }
        }
    }

    cout << setprecision(10) << result << '\n';

}