N = int(input())
A = [0]+sorted(list(map(int,input().split())))
B = [0]+sorted(list(map(int,input().split())))
cnt = 0
for i in range(1,N):
    cnt += abs(B[i]-A[i+1])
cmin = cnt
ans = [A[1]]
for i in range(2,N+1):
    cnt += abs(B[i-1]-A[i-1])-abs(B[i-1]-A[i])
    if cnt<cmin:
        cmin = cnt
        ans = [A[i]]
    elif cnt==cmin:
        ans.append(A[i])
ans = sorted(list(set(ans)))
print(len(ans))
print(*ans)