from bisect import bisect_left

n, m, q = map(int, input().split())
xy = [list(map(int, input().split())) for _ in range(q)]
xy.sort(key = lambda x:(x[0], -x[1]))
lst = []
for _, y in xy:
    p = bisect_left(lst, y)
    if p == len(lst):
        lst.append(p)
    else:
        lst[p] = y
print(len(lst))