import sys
input = sys.stdin.readline
import bisect

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

ab.sort(key=lambda x:(x[0],-x[1]))

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
    res=bisect.bisect_left(dp,max_value)
    return res

inf=1<<30
bl = [b for a,b in ab]
ans=LIS(bl,max_value=inf)
print(ans)