#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);++i)

int main(){
	int N;
	cin>>N;
	vector<int> A(N),B(N-1);
	rep(i,N)cin>>A[i];
	rep(i,N-1)cin>>B[i];
	sort(A.begin(),A.end());
	sort(B.begin(),B.end());
	
	vector<long> L(N,0),R(N,0);
	rep(i,N-1) L[i+1]=L[i]+abs(A[i]-B[i]);
	for(int i=N;--i;) R[i-1]=R[i]+abs(A[i]-B[i-1]);
	long mi=1e18;
	rep(i,N) mi=min(mi, L[i]+R[i]);
	vector<int> ans;
	rep(i,N) if(mi==L[i]+R[i]&&(ans.empty()||ans.back()!=A[i])) ans.push_back(A[i]);
	cout<<ans.size()<<endl;
	for(long e:ans)cout<<e<<" ";
	cout<<endl;
}