n=int(input())
a=list(map(int,input().split()))
l={}
r={}
for i in range(n):
	l[a[i]]=0
	r[a[i]]=0
for i in range(n):
	l[a[i]]+=1
c=0
for v in r:
	c+=l[v]>1 or r[v]>1
ans=[]
for i in range(n-1):
	c-=l[a[i]]>1 or r[a[i]]>1
	l[a[i]]+=1
	r[a[i]]-=1
	c+=l[a[i]]>1 or r[a[i]]>1
	if c==0:
		ans+=[i+1]
print(len(ans))
print(*ans)