#coding:utf-8

N=input()
A=map(int,raw_input().split())
A=sorted(A)

cnt=0
for i in range(N-1):
	if A[i-1]!=A[i] and A[i]!=A[i+1]:
		cnt+=1
	
if A.count(A[-1]) == 1:
	cnt+=1

print cnt