#include <iostream>
#include <vector>
#include <algorithm>
#include <set>


int main(){
	int N;
	std::cin >> N;
	std::vector<int> A(N), B(N - 1);
	for(int i = 0; i < N; ++i) std::cin >> A[i];
	for(int i = 0; i < N - 1; ++i) std::cin >> B[i];
	std::sort(A.begin(), A.end());
	std::sort(B.begin(), B.end());
	std::vector<long long> bad(N, 0);
	for(int i = 0; i < N - 1; ++i){
		bad[N - 1] += abs(A[i] - B[i]);
	}
	for(int i = N - 1; i > 0; --i){
		bad[i - 1] = bad[i] - abs(A[i - 1] - B[i - 1]) + abs(A[i] - B[i - 1]);
	}
	long long min_value = 0x7FFFFFFFFFFFFFFF;
	for(long long value : bad){
		min_value = std::min(min_value, value);
	}
	std::vector<int> ans;
	for(int i = 0; i < N; ++i){
		if(bad[i] == min_value) ans.push_back(i);
	}
	std::set<int> ans2;
	for(int a : ans) ans2.insert(A[a]);
	std::cout << ans2.size() << std::endl;
	for(int a : ans2) std::cout << a << " ";
	puts("");
	return 0;
}