import bisect
import sys
readline=sys.stdin.readline

def LIS(lst,weakly=False,max_value=float('inf')):
    f=bisect.bisect_right if weakly else bisect.bisect_left
    dp=[max_value]*(min(N,M)+1)
    for x in lst:
        i=f(dp,x)
        dp[i]=x
    n=bisect.bisect_left(dp,max_value)
    return n

N,M,Q=map(int,readline().split())
AB=[[0]*M for i in range(N)]
for _ in range(Q):
    a,b=map(int,readline().split())
    a-=1
    b-=1
    AB[a][b]=1
lst=[]
for a in range(N):
    for b in range(M-1,-1,-1):
        if AB[a][b]:
            lst.append(b)
inf=1<<30
ans=LIS(lst,max_value=inf)
print(ans)