def main():
    N = int(input())
    nums = [int(i) for i in input().split()]
    print(get_new_num_count(nums))

def get_new_num_count(values):
    ans = 0
    set_values = set(values)
    for value in set_values:
        count = values.count(value)
        if count == 1:
            ans += 1
    return ans


if __name__ == '__main__':
    main()