from itertools import accumulate

N=int(input())
A=sorted(list(map(int, input().split())))
B=sorted(list(map(int, input().split())))
maena=[0]
usina=[]
for a,b in zip(A[1:],B):
  maena.append(abs(a-b))
for a,b in zip(A[:N-1],B):
  usina.append(abs(a-b))
usina.append(0)
mem=[[sum(maena),A[0]],[sum(usina),A[-1]]]

u_rui=list(accumulate(usina))
m_rui=list(accumulate(maena[::-1]))[::-1]

for i in range(1, N-1):
  mem.append([u_rui[i-1]+m_rui[i+1],A[i]])

ans=10**18+1
ans_s=[]
for a,b in mem:
  if a < ans:
    ans_s=[b]
    ans = a
  elif a == ans:
    ans_s.append(b)

f_a=set(sorted(ans_s))
print(len(f_a))
print(*f_a)