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

scr=sum(abs(A[i]-B[i]) for i in range(N-1))
ach=[N-1]
now=scr
for i in range(N-2,-1,-1):
    now-=abs(A[i]-B[i])
    now+=abs(A[i+1]-B[i])
    if now==scr : ach.append(i)
    if now<scr : scr=now ; ach=[i]

ans=set(A[i] for i in ach)
print(len(ans))
print(*sorted(list(ans)))