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

A.sort()
B.sort()

ans = [0] * N
a = 0
for i in range(N):
  ans[i] += a
  if i != N - 1:
    a += abs(A[i] - B[i])

a = 0
for i in range(N - 1, -1, -1):
  ans[i] += a
  if i != 0:
    a += abs(A[i] - B[i - 1])

R = {}
Ans = []
a = min(ans)
for i in range(N):
  if ans[i] == a and A[i] not in R:
    R[A[i]] = 1
    Ans.append(A[i])

print(len(Ans))
print(*Ans)