N = int(input())
A = list(map(int,input().split()))

from collections import defaultdict
h = defaultdict(int)
hh = 0
m = defaultdict(int)
mm = 0
for a in A:
	m[a] += 1
	if m[a] == 2:
		mm += 1

ans = []
for j in range(N - 1):
	a = A[j]
	h[a] += 1
	if h[a] == 2:
		hh += 1
	m[a] -= 1
	if m[a] == 1:
		mm -= 1
	if hh == 0 and  mm == 0:
		ans.append(j + 1)
print(len(ans))
print(*ans)