#include <bits/stdc++.h>
using namsepace std;
int a,b,c,d,e,f;
double s,zc;
int juli(int x1,int y1,int x2,int y2)
{
    s==sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
    return s;
}
int main()
{
    cin>>a>>b>>c>>d>>e>>f;
    zc==juli(a,b,c,d)+juli(a,b,e,f)+juli(c,d,e,f);
    cout<<zc;
    return 0;
}