Problem:
Distance

Write a program which calculates the distance between two points P1(x1, y1) and P2(x2, y2).

Input

Four real numbers x1, y1, x2 and y2 are given in a line.

Output

Print the distance in real number. The output should not contain an absolute error greater than 10-4.

Sample Input

0 0 1 1

Sample Output

1.41421356

Solution in C# (judge verdict: Accepted)

using System;

class Program
{
    static void Main()
    {
    	var s = Console.ReadLine().Split(' ');
    	var x1 = double.Parse(s[0]);
    	var y1 = double.Parse(s[1]);
    	var x2 = double.Parse(s[2]);
    	var y2 = double.Parse(s[3]);
    	
    	Console.WriteLine( Math.Sqrt( (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2) ) );
    }
}