using System;

public class Program

{

    public static void Main()

    {

        double x1 , x2 , x3 , x4 , y1 ,  y2 , y3 , y4 ;

Console.WriteLine("x1" );

        x1=double.Parse(Console.ReadLine());

Console.WriteLine("x2" );

        x2=double.Parse(Console.ReadLine());

Console.WriteLine("x3" );

        x3=double.Parse(Console.ReadLine());

Console.WriteLine("x4" );

        x4=double.Parse(Console.ReadLine());

Console.WriteLine("y1" );

        y1=int.Parse(Console.ReadLine());

Console.WriteLine("y2" );

        y2=int.Parse(Console.ReadLine());

Console.WriteLine("y3" );

        y3=int.Parse(Console.ReadLine());

Console.WriteLine("y4" );

        y4=double.Parse(Console.ReadLine());

        Console.WriteLine("mo7et {0}",(Math.Sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2))+Math.Sqrt((x1-x3)*(x1-x3)+(y1-y3)*(y1-y3)))+Math.Sqrt((x2-x4)*(x2-x4)+(y2-y4)*(y2-y4))+Math.Sqrt((x3-x4)*(x3-x4)+(y3-y4)*(y3-y4)));

    }

}