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=[usina[0]]
for i in range(1,len(usina)):
  u_rui.append(u_rui[-1]+usina[i])

m_rui=[0]*len(maena)
m_rui[-1] = maena[-1]
for i in range(1,len(maena)):
  m_rui[-i-1] = m_rui[-i]+maena[-i-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)