from bisect import bisect_left

n, m, q = map(int, input().split())
Q = [list(map(int, input().split())) for _ in range(q)]

Q.sort(key=lambda x: (x[0], x[1]))
LIS = []
for i in range(q):
    b = Q[i][1]
    idx = bisect_left(LIS, b)
    if idx == len(LIS):
        LIS.append(b)
    else:
        LIS[idx] = b
print(len(LIS))