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):
    sorted_values = sorted(values)
    first_loop = True
    duplicate = []
    for value in sorted_values:
        if first_loop:
            prev = value
            first_loop = False
            continue
        if prev == value:
            duplicate.append(prev)
        prev = value
    #print("values", values)
    #print("duplicate", duplicate)
    return len(set(values)) - len(set(duplicate))


if __name__ == '__main__':
    main()