from collections import Counter
N = int(input())
A = list(map(int, input().split()))
S = Counter()
T = Counter(A)
X = 0
Y = len(T)

ans = []
for i, a in enumerate(A, 1):
   S[a] += 1
   if S[a] == 1:
      X += 1
   T[a] -= 1
   if T[a] == 0:
      Y -= 1
      del T[a]
   if X == i and Y == N-i and i != N:
      ans.append(i)

print(len(ans))
print(*ans)