def game(start, n):
	d = dict()
	for i, x in enumerate(start[:-1]):
		d[x] = i
	last = start[-1]

	for i in range(len(start), n):
		if last in d:
			j = d[last]
			d[last] = i - 1
			last = i - 1 - j
		else:
			d[last] = i - 1
			last = 0

	return last


print(game([11, 18, 0, 20, 1, 7, 16], 2020))
print(game([11, 18, 0, 20, 1, 7, 16], 30000000))