N = int(raw_input())
A = map(int,raw_input().split())
B = {}
c = 0
for i in range(N):
	if B.has_key(A[i]):
		B[A[i]] += 1
	else:
		B[A[i]] = 1
for key in B.keys():
	if B[key] == 1:
		c += 1
print c