from bisect import bisect_left
N, M, Q = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(Q)]
B = [0]*Q
for i in range(Q):
    a, b = A[i]
    c = 2**10-1-b
    B[i] = a*(2**10)+c
B.sort()

INF = 10**9
dp = [INF]*(N+M+1)
dp[0] = 0

for v in B:
    b = 2**10-1-(v % (2**10))
    ind = bisect_left(dp, b)
    dp[ind] = min(dp[ind], b)

ans = 0
while dp[ans+1] < INF:
    ans += 1
print(ans)