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.Linq;class P{static void Main(){var a=Console.ReadLine().Split().Select(double.Parse).ToList();Console.WriteLine(Math.Sqrt(Math.Pow(a[3]-a[1],2)+Math.Pow(a[2]-a[0],2)));}}