def main():
    n = int(input())
    list_a = [int(i) for i in input().split(" ")]
    counts = {}
    for a in list_a:
        counts[a] = counts.get(a, 0) + 1

    ans_count = 0
    for count in counts.values():
        if count == 1:
            ans_count += 1

    print(ans_count)


if __name__ == "__main__":
    main()