n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
a.sort()
b.sort()
ad=[0]*n
adr=[0]*n
for i in range(n-1):
	ad[i]=abs(a[i]-b[i])
for i in range(n-1,0,-1):
	adr[i]=abs(a[i]-b[i-1])
for i in range(1,n-1):
	ad[i]+=ad[i-1]
for i in range(n-2,0,-1):
	adr[i]+=adr[i+1]
ans = int(1e18)
p =[]
for i in range(n):
	if i == 0:
	    now=adr[1]
	elif i == n-1:
		now=ad[n-2]
	else:
		now=ad[i-1]+adr[i+1]
	if now < ans:
		ans=now
		p.clear()
		p.append(a[i])
	elif now==ans:
		p.append(a[i])
p=list(set(p))
print(len(p))
print(*p)