mod = 1000000007
eps = 10**-9


def main():
    import sys
    from bisect import bisect_left
    input = sys.stdin.readline

    N, M, Q = map(int, input().split())
    XY = [[0] * (M+1) for _ in range(N+1)]
    for _ in range(Q):
        x, y = map(int, input().split())
        XY[x][y] = 1

    LIS = [0]
    for x in range(1, N+1):
        for y in range(M, 0, -1):
            if XY[x][y] == 0:
                continue
            j = bisect_left(LIS, y)
            if j == len(LIS):
                LIS.append(y)
            else:
                LIS[j] = y
    print(len(LIS) - 1)


if __name__ == '__main__':
    main()