#include	<bits/stdc++.h>
using	namespace	std;

int	main() {
	double x1, y1, x2, y2, x3, y3;
	cin >>x1 >>y1 >>x2 >>y2 >>x3 >>y3;
	double u1=x3-x1;
	double v1=y3-y1;
	double u2=x2-x1;
	double v2=y2-y1;
	double u3=x3-x2;
	double v3=y3-y2;
	double a=sqrt(u1*u1+v1*v1);
	double b=sqrt(u2*u2+v2*v2);
	double c=sqrt(u3*u3+v3*v3);
	double l=max(max(a, b), c);
	double r=u1*v2-v1*u2;
	r /=(a+b+c);
	if (r<0)
		r = -r;
	double x=l*r/(l+2*r);
	cout <<setprecision(10) <<x <<endl;
	return 0;
};
