n=int(input())
a=[int(i) for i in input().split()]
a.sort()
ans=0
if len(a)==1:
    ans=1
else:
    for i in range(len(a)):
        if i==0:
            if a[i]!=a[i+1]:
                ans+=1
        elif i==len(a)-1:
            if a[i]!=a[i-1]:
                ans+=1
        else:
            if a[i]!=a[i-1] and a[i]!=a[i+1]:
                ans+=1
print(ans)