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