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