n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
a.sort()
b.sort()
l=[0]*n
for i in range(n-1):
  l[i+1]=abs(a[i]-b[i])
  l[i+1]+=l[i]
r=[0]*n
for i in range(n-1):
  r[i+1]=abs(a[~i]-b[~i])
  r[i+1]+=r[i]
m=min(l[i]+r[n-1-i] for i in range(n))
c=[]
for i in range(n):
  if l[i]+r[n-1-i]==m:
    c+=[a[i]]
c=set(c)
print(len(c))
print(*c)