n = int(input())
a = sorted(map(int, input().split()))
b = sorted(map(int, input().split()))
sf = [0] * (n + 1)
sb = [0] * (n + 1)
for i in range(n - 1):
    sf[i+1] = sf[i] + abs(a[i] - b[i])
for i in range(n - 1, 0, -1):
    sb[i] = sb[i+1] + abs(a[i] - b[i-1])
mn = min(sf[i] + sb[i+1] for i in range(n))
ans = []
for i in range(n):
    if sf[i] + sb[i+1] == mn:
        if ans and ans[-1] == a[i]:
            continue
        ans.append(a[i])
print(len(ans))
print(*ans)