N = int(input())
l = list(map(int, input().split()))
l.sort()
count = 0
ck = 0

if N == 1:
    count = 1
else:
    for i in range(N-1):
        if l[i] != l[i+1] and l[i] != ck:
            count += 1
            # print(l[i])
        ck = l[i]
    if l[-1] != ck:
        count += 1
    # print("aa")

print(count)