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

LA = [ 0 ] * (N)
LB = [ 0 ] * (N)

for i in range(N-1) :
    LA[i+1] = LA[i] + abs(A[i]-B[i])
    LB[N-2-i] = LB[N-1-i] + abs(A[N-1-i]-B[N-2-i])

RES = []
for i in range(N) :
    RES.append( LA[i] + LB[i] )

ANS = min( RES )
res = []
ans = 0
for i in range(N) :
    if RES[i] == ANS :
        ans += 1
        if A[i] not in res :
            res.append(A[i])

res.sort()

print( ans )
for i in res :
    print( i , end = " " )