import math


def get_elapsed_time(start, end):
    """
    Compute elapsed time.

    @param start: start time
    @param end:   end time
    @return:      elapsed time (string)
    """
    diff = end - start
    days, hours, minutes = [0, 0, 0]
    s_time = []
    if diff > 86400:  # day
        days = math.floor(diff / 86400)
        diff = diff - days * 86400
    if diff > 3600:   # hour
        hours = math.floor(diff / 3600)
        diff = diff - hours * 3600
    if diff > 60:     # minute
        minutes = math.floor(diff / 60)
        diff = diff - minutes * 60

    if days > 0:
        s_time = "{0} days {1} hrs {2} min {3:.4f} sec".format(days, hours, minutes, diff)
        # print(f"{days} days {hours} hrs {minutes} min {diff:.4f} sec")
    elif hours > 0:
        s_time = "{0} hrs {1} min {2:.4f} sec".format(hours, minutes, diff)
        # print(f"{hours} hrs {minutes} min {diff:.4f} sec")
    elif minutes > 0:
        s_time = "{0} min {1:.4f} sec".format(minutes, diff)
        # print(f"{minutes} min {diff:.4f} sec")
    else:
        s_time = "{0:.4f} sec".format(diff)
        # print(f"{diff: .4f} sec")

    return s_time