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

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

S = set()
MIN = min(C)
for i in range(N):
    if C[i] == MIN:
        S.add(A[i])

ans = sorted(S)
print(len(ans))
print(*ans)