Write a program that calculates the distance between two points in a Cartesian coordinate system.

Input Format Input will be in the form:

X1 Y1 X2 Y2

Where:

(X1, Y1) = Coordinates of the first point.

(X2, Y2) = Coordinates of the second point.

Output Format

Your output should be rounded to the nearest two decimals places

Sample 1:

Input 0 0 2 2

Output 2.83

Sample 2:

Input 1 10 15 20 Output 17.20