#import sys
# input = sys.stdin.readline
def mp():return map(int,input().split())
def lmp():return list(map(int,input().split()))
def mps(A):return [tuple(map(int, input().split())) for _ in range(A)]
import math
import bisect
import heapq
from copy import deepcopy as dc
from itertools import accumulate
from collections import Counter, defaultdict, deque
def ceil(U,V):return (U+V-1)//V
def modf1(N,MOD):return (N-1)%MOD+1
inf = int(1e20)
mod = int(1e9)+7
def lis(seq):
    LIS = [seq[0]]
    for i in range(len(seq)):
        if seq[i] > LIS[-1]:
            LIS.append(seq[i])
        else:
            LIS[bisect.bisect_left(LIS, seq[i])] = seq[i]
    return len(LIS)

n,m,q = mp()
p = mps(q)
p.sort()
pa = [p[0]]
y = [p[0][1]]
for i in range(1,q):
    if pa[-1][0] != p[i][0]:
        pa.append(p[i])
        y.append(p[i][1])

print(lis(y))