import sys
input = sys.stdin.readline

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

ab.sort()
li = []
for a,b in ab:
    li.append(b)

def LIS(L):
  from bisect import bisect_left
  seq = []
  for ai in L:
    pos = bisect_left(seq, ai)
    if len(seq) <= pos:
      seq.append(ai)
    else:
      seq[pos] = ai
  return len(seq)

print(LIS(li))