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

A.sort()
B.sort()
inf = float("INF")
dp = [inf] * n
dp[-1] = 0
for i in range(n-2, -1, -1):
    a = A[i+1]
    b = B[i]
    dp[i] = dp[i+1] + abs(a - b)

ans = dp[0]
tmp = 0
D = [0]
for i in range(n-1):
    tmp += abs(A[i] - B[i])
    D.append(tmp)
    ans = min(ans, tmp + dp[i+1])

Ans = set()
for i in range(n):
    if D[i] + dp[i] == ans:
        Ans.add(A[i])
Ans = list(Ans)
Ans.sort()
print(len(Ans))
print(*Ans)