N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
v1=[0]*(N+1)
v2=[0]*(N+1)
A.sort()
B.sort()
for i in range(N-1):
  v1[i]=v1[i-1]+abs(A[i]-B[i])
for i in range(N-1,0,-1):
  v2[i]=v2[i+1]+abs(B[i-1]-A[i])
ans=10**18
for i in range(N-1):
  ans=min(ans,v1[i-1]+v2[i+1])
result=[]
for i in range(N):
  k=v1[i-1]+v2[i+1]
  if k==ans:
    result.append(A[i])
result=set(result)
result=list(result)
result.sort()
print(len(result))
print(*result)