N = int(input())
listA = [int(i) for i in input().split()]
listA.sort()

count = 0
for i in range(len(listA)):
    if i == 0:
        if listA[i] != listA[(i+1)]:
            count += 1
    elif i == len(listA)-1:
        if listA[(i-1)] != listA[i]:
            count += 1
    else:
        if listA[(i-1)] != listA[i] and listA[i] != listA[(i+1)]:
            count += 1

print(count)