from collections import defaultdict
dp=defaultdict(int)
f=defaultdict(int)
indf=-1
N=int(input())
A=list(map(int,input().split()))
ind2=len(A)
for a in range(N):
    if dp[A[a]]==2:
        print(0)
        exit()
    elif dp[A[a]]==1:
        indf = max(indf,f[A[a]])
        ind2=min(ind2,a)
    elif dp[A[a]]==0:
        f[A[a]]=a
    dp[A[a]]+=1
if ind2==len(A):
    print(N-1)
    print(*[i+1 for i in range(N-1)])
    exit()
ans= [i+1 for i in range(indf,ind2)] 
print(len(ans))
print(*ans)