N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))

A.sort()
B.sort()

SA=[0]

for i in range(N-1):
    SA.append(SA[-1]+abs(B[i]-A[i]))

A.reverse()
B.reverse()

SB=[0]

for i in range(N-1):
    SB.append(SB[-1]+abs(B[i]-A[i]))

SB.append(0)
SB.append(0)
SB.reverse()
A.reverse()
ANS=1<<60
LIST=[]

for i in range(len(SA)):
    x=SA[i]+SB[i+2]

    if x<ANS:
        ANS=x
        LIST=[A[i]]
    elif x==ANS:
        LIST.append(A[i])

LIST=sorted(set(LIST))

print(len(LIST))
print(*LIST)