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

A.sort()
B.sort()

diff = 0
for a, b in zip(A[1:], B):
    diff += abs(a-b)

result = set([A[0]])
min_d = diff

for i in range(1, N):
    diff += abs(A[i-1]-B[i-1]) - abs(A[i]-B[i-1])
    if min_d < diff:
        continue
    if min_d > diff:
        result.clear()
    result.add(A[i])
    min_d = diff

print(len(result))
print(*list(result))