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

S = 0
A.sort()
B.sort()

C = A[:-1]

for i in range(N - 1):
    S += abs(B[i] - C[i])

min_S = S

ans = [A[-1]]

for i in range(-1, -N, -1):
    S = S + (B[i] - abs(B[i] - C[i]))
    C[i] = A[i]
    S += abs(B[i] - C[i]) - B[i]
    
    if S < min_S:
        min_S = S
        ans = [A[i - 1]]
    
    elif S == min_S:
        ans.append(A[i - 1])

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

# print(A)
# print(B)
# print(C)
# print(S)