H,W,Q = map(int,input().split()) room = {} count = H*W for _ in range(Q): y,x = map(int,input().split()) if x not in room: room[x] = [y] count -= H-y+1 else: min_room = min(room[x]) if y < min_room: count -= min_room-y room[x].append(y) print(count)