import math


def calculate_distance(x1, y1, x2, y2):
    """ (float, float, float, float) -> float
    Calculate distance between two coordinates on the map
    >>> calculate_distance(43.45, 51.1345, 12.456, -50.34)
    106.1023194197469
    """
    dist = math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2)
    return dist