N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
A.sort()
B.sort()
cum1=[0]*N
cum2=[0]*N
for i in range(N-1):
    cum1[i+1]=cum1[i]+abs(A[i]-B[i])
    cum2[-i-2]=cum2[-i-1]+abs(A[-i-1]-B[-i-1])
ans=1<<60
for i in range(N):
    ans=min(ans,cum1[i]+cum2[i])
fin=set()
for i in range(N):
    if cum1[i]+cum2[i]==ans:
        fin.add(A[i])
print(len(fin))
print(*sorted(fin))