import itertools

lgt = int(input())
dat = list(map(int, input().split()))
ans = 0
for i in itertools.combinations(dat, 2):
    if i[0] == i[1]:
        for j in range(lgt):
            if i[0] == dat[j]:
                dat[j] = -1
for i in dat:
    if i != -1:
        ans += 1
print(ans)