def main():
	import sys
	input = sys.stdin.buffer.readline
	n, m, q = map(int, input().split())
	ab = [list(map(int, input().split())) for i in range(q)]
	ab.sort(key=lambda x: (x[0], -x[1]))
	INF = 10 ** 9
	from bisect import bisect_left
	dp = [INF] * (q + 1)
	for a, b in ab:
		dp[bisect_left(dp, b)] = b
	print(bisect_left(dp, INF))
if __name__ == '__main__':
	main()