from collections import defaultdict import sys input = sys.stdin.readline h, w, q = map(int, input().split()) ans = h * w N = defaultdict(int) for _ in range(q): y, x = map(int, input().split()) prev = N[x] curr = h - y + 1 if curr > prev: dif = curr - prev ans -= dif N[x] = curr print(ans)