from collections import Counter

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

rfreq = Counter()
rdup = 0
for i in range(N):
    rfreq[A[i]] += 1
    if rfreq[A[i]] == 2:
        rdup += 1

ans = []
lfreq = Counter()
for i in range(N-1):
    lfreq[A[i]] += 1
    if lfreq[A[i]] == 2:
        break

    rfreq[A[i]] -= 1
    if rfreq[A[i]] == 1:
        rdup -= 1

    if rdup == 0:
        ans.append(i+1)

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