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 Python3 (judge verdict: Accepted)

import math

px, py, qx, qy = map(float,input().split())
pq = (qx - px) ** 2 + (qy - py) ** 2

print(math.sqrt(pq))