from collections import defaultdict
n=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
A.sort()
B.sort()
S=[]
for i in range(n-1):
    S.append((abs(B[i]-A[i]),abs(B[i]-A[i+1])))
T=sum(i for j,i in S)
D=defaultdict(list)
D[T].append(A[0])
for i in range(n-1):
    a,b=S[i]
    T=T-b+a
    D[T].append(A[i+1])
m=min(i for i in D.keys())
SS=set(D[m])
print(len(SS))
SS=list(SS)
SS.sort()
print(*SS)