*#include<bits/stdc++.h> using namespace std; double b(double x1,double y1,double x2,double y2){ double t1=pow (x2-x1,2); double t2=pow (y2-y1,2); return sqrt(t1+t2); } int main(){ double x1,x2,y1,y2,x3,y3,sss=0; cin>>x1>>y1>>x2>>y2>>x3>>y3; sss+=b( x1, y1, x2, y2); sss+=b( x3, y3, x2, y2); sss+=b( x1, y1, x3, y3); printf("%.1lf",sss); return 0; }