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

A.sort()
B.sort()

now = 0
for i in range(N-1):
    now += abs(A[i+1] - B[i])

mind = now
for i in range(N-1):
    now -= abs(A[i+1] - B[i])
    now += abs(A[i] - B[i])
    mind = min(mind, now)

now = 0
ansL = set()
for i in range(N-1):
    now += abs(A[i+1] - B[i])
if now == mind:
    ansL.add(A[0])
# print('ansL', ansL)
for i in range(N-1):
    now -= abs(A[i+1] - B[i])
    now += abs(A[i] - B[i])
    if now == mind:
        ansL.add(A[i+1])
# print('ansL', ansL)

print(len(ansL))
ans = list(ansL)
ans.sort()
print(*ans)