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

d1 = [abs(A[i] - B[i]) for i in range(N - 1)]
d2 = [abs(A[i + 1] - B[i]) for i in range(N - 1)]
cum_d1 = [0] * N
cum_d2 = [0] * N
for i in range(N - 1):
    cum_d1[i + 1] = cum_d1[i] + d1[i]
    cum_d2[i + 1] = cum_d2[i] + d2[i]

mn_val = 1 << 60
ans = []
for i in range(N):
    val = cum_d1[i] + cum_d2[-1] - cum_d2[i]
    if val < mn_val:
        mn_val = val
        ans = [A[i]]
    elif val == mn_val:
        ans.append(A[i])
ans = sorted(set(ans))
print(len(ans))
print(*ans)