#include <bits/stdc++.h>
using namespace std;
#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second
const int M = 1e9+7;
const int inf = 1e18;
int bp(int x, int y, int p){
int res = 1;
x = x % p;
while (y > 0) {
if (y & 1)
res = (res * x) % p;
y = y >> 1;
x = (x * x) % p;
}
return res;
}
int MI(int n, int p){
return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
return x * 1ull * y % p;
}
int di(int x,int y, int p){
return mul(x, MI(y, p), p);
}
int n , m , k , q;
map<int,int>ind,have;
void solve(int testcase_number){
cin>>n>>k;
input(int,a,n+k);
sort(all(a));
set<int>sum;
for(int i = 0;i<=k;i++){
for(int j = 0;j<=k;j++){
int r = n+k-1-j;
if(i!= r){
sum.insert(a[i]+a[r]);
}
}
}
for(int i = 0;i<n+k;i++){
ind[a[i]] = i+1;
have[a[i]] = 1;
}
print(sum);
for(auto i:sum){
vector<int>vis(n+k+1,0);
int ans = 0;
vector<pair<int,int>>aa;
for(int j = 0;j<n+k;j++){
if(have[i-a[j]] and ind[i-a[j]] > 0 and !vis[j+1] and !vis[ind[i-a[j]]]){
ans++;
aa.pb({a[j],i-a[j]});
// aa.pb(i-a[j]);
vis[j+1] = 1;
vis[ind[i-a[j]]] = 1;
}
}
if(ans>=n/2){
vector<int>fans;
for(auto i:aa){
fans.pb(i.fi);
fans.pb(i.se);
if(fans.size() == n){
break;
}
// cout<<i.fi<<" "<<i.se<<" ";
}
sort(all(fans));
print(fans);
// cout<<endl;
return;
}
}
}
signed main(){
ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
cin.tie(0), cout.tie(0);
cout << fixed<<setprecision(9);
int t = 1;
// cin>>t;
for(int i = 1;i<=t;i++){
solve(i);
}
}
