import math

## distance(x_one, y_one, x_two, y_two) produces the distance between
##    points (x_one, y_one) and (x_two, y_two).
## distance: (anyof Float Int) (anyof Float Int) 
##           (anyof Float Int) (anyof Float Int) -> Float
def distance(x_one, y_one, x_two, y_two):
    x_diff = x_one - x_two
    y_diff = y_one - y_two
    sum_of_squares = pow(x_diff, 2) + pow(y_diff, 2)
    return math.sqrt(sum_of_squares)