class Problem0182:
	def solve(this):
		n = int(input())
		a = list(map(int, input().split()))
		
		res = {}
		for d in a:
			res[d] = res.get(d, 0) + 1
		
		cnt = 0
		for d in res.values():
			if d == 1:
				cnt += 1
		print(cnt)
		
if __name__ == "__main__":
	problem = Problem0182()
	problem.solve()