from random import random
from math import log

def intensity(t):
	if 0<=t and 20>t:
		return 8
	elif 20<=t and t<40:
		return 4
	else:
		return 8

lamd = (8/20.+4/20.+8/20.)/3 # мат ожидание
end_time = 60

current_time = 0
events = []

while(True):
	r = random()
	current_time = current_time - 1 / lamd * log(r,2)
	if current_time > end_time:
		break
	r = random()
	if r <= intensity(current_time)/lamd:
		events.append(current_time)

print('Время прихода: ')
for event in events:
	print("%.2f" % event)

print("Количество событий: ", len(events))