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;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication48
{
    class Program
    {
        static void Main(string[] args)
        {
            double[] a = Console.ReadLine().Split().Select(double.Parse).ToArray();
            double b = a[0] - a[2];
            double c = a[1] - a[3];
            b = b * b;
            c = c * c;
            double d = b + c;
            d = Math.Sqrt(d);
            Console.WriteLine(d);
        }
    }
}