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

pre_costs = [0 for _ in range(N)]
suf_costs = [0 for _ in range(N)]
for i in range(1, N):
    pre_costs[i] = abs(A[i - 1] - B[i - 1]) + pre_costs[i - 1]
    suf_costs[-(1 + i)] = abs(A[-i] - B[-i]) + suf_costs[-i]

min_cost = 10 ** 18
for i in range(N):
    min_cost = min(min_cost, pre_costs[i] + suf_costs[i])

ans = set()
for i in range(N):
    if pre_costs[i] + suf_costs[i] == min_cost:
        ans.add(A[i])

print(len(ans))
print(*ans)