import sys

input=sys.stdin.readline
N,M,Q=map(int,input().split())
E=[[0]*(M+1) for _ in range(N+1)]

for _ in range(Q):
    a,b=map(int,input().split())
    E[a][b]=1

for i in range(1,N+1):
    x=E[i]; xx=E[i-1]
    for j in range(1,M+1):
        x[j]+=max(x[j-1], xx[j])

print(E[N][M])