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

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

right = [0]
for i in range(N-1):
    right.append(right[-1]+abs(A[N-i-1]-B[N-i-2]))

INF = 1<<62
ans = INF
S = set()
for i in range(N):
    num = left[i]+right[N-i-1]
    if num < ans:
        ans = num
        S = set([A[i]])
    elif num == ans:
        S.add(A[i])

print(len(S))
print(*list(S))