from sys import stdin
pin=stdin.readline

def lcs(N,M,check):
  dp=[[0]*(M+1)for _ in[0]*(N+1)]
  for i in range(1,N+1):
    for j in range(1,M+1):
      if check[i-1][j-1]==1:
        dp[i][j]=dp[i-1][j-1]+1
      else:
        dp[i][j]=max(dp[i-1][j],dp[i][j-1])
  return dp[N][M]

def main():
  N,M,Q=map(int,pin().split())
  check=[[0]*M for _ in[0]*N]
  for _ in[0]*Q:
    a,b=map(int,pin().split())
    check[a-1][b-1]=1
  print(lcs(N,M,check))
  return

main()