n = int(input())
a = list(map(int, input().split()))
a.sort()

count = 1

if a[1] == a[0]:
        count -= 1
else :
    count += 1

for i in range(2,n):
    if a[i] == a[i-1]:
        if a[i] != a[i-2]:
            count -= 1
    else:
        count += 1

print(count)