n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
a.sort()
b.sort()
mn = [0]*n
for i in range(n-1):
    mn[i+1] = mn[i] + abs(a[i] - b[i])

mx = [0]*n
for i in reversed(range(1, n)):
    mx[i-1] = mx[i] + abs(a[i] - b[i-1])

ans = 10**18
g = []
for i in range(n):
    if mn[i] + mx[i] < ans:
        ans = mn[i] + mx[i]
        g = [a[i]]
    elif mn[i] + mx[i] == ans:
        g.append(a[i])

g = sorted(set(g))
print(len(g))
print(*g)