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 PHP (judge verdict: Wrong Answer)

<?php

$input=trim(fgets(STDIN));

$array_data=explode(" " , $input);

print_r($array_data);

$x1=$array_data[0];
$y1=$array_data[1];
$x2=$array_data[2];
$y2=$array_data[3];



print sqrt(pow(($x2-$x1),2)+pow(($y2-$y1),2));