#N,K=map(int, input().split())
#A=list(map(int, input().split()))
N=int(input())
A=list(map(int, input().split()))
D={}
for i in range(N):
  a=A[i]
  if a not in D:
    D[a]=[]
  D[a].append(i)
  
l,r=1,N-1
ans=[]
for d in D:
  if len(D[d])>2:
    print(0)
    print(*ans)
    exit()
  if len(D[d])==2:
    ll,rr=D[d][0]+1,D[d][1]
    l=max(l,ll);r=min(r,rr)

if l<=r:
  ans=[i for i in range(l,r+1)]
  print(len(ans))
  print(*ans)
else:
  print(0)
  ans=[]
  print(*ans)