n=int(input())
l=[int(i) for i in input().split()]
l.sort()

count=0
for i in range(n):
    j=0
    jud=0
    while j!=n:
        if l[i]==l[j] and i!=j:
            jud+=1
        j+=1
    if jud==0:
        count+=1

print(count)