#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned ll
#define nl "\n"
#define sz(x) int(x.size())
#define NumOfDigit(w) log10(w) + 1
#define fill(arr, val)  memset(arr, val , sizeof(arr))
#define PI 3.141592654
#define ceil(w, m) (((w) / (m)) + ((w) % (m) ? 1 : 0))
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define fi first
#define se second
#define cin(v) for (auto&i:v) cin >> i;
#define cout(v) for (auto&i:v) cout << i << " ";
#define fixed(n) fixed << setprecision(n)
//#define MOD  1e9 + 7


void IO(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
}
void files(){
    //freopen("filename.in" , "r" ,stdin);
            #ifndef ONLINE_JUDGE
              freopen("input.txt", "r", stdin);  freopen("output.txt", "w", stdout);
            #endif
}


void solve(){


ll n  ;
cin >> n ;

n <<=1;


ll x ,start=-1  , end =-1 , cnt=0;

for(ll i=1;i<=n;i++){


    cin >> x;


   if( start == -1 ){ // i=1
       start = x;
       end = x+ x/3 ;
      // cout << x << " ";
   }



    if( x < end ) {
       cout << x << " ";
   }
   else if( x > end ) {
       cout << x << " ";
       start = x , end = x + x/3;
       cnt=0;
   }

}


}

int main(){
             //    IO();       //  files();

cin.tie(0);
cout.tie(0);
ios::sync_with_stdio(0);

    int testCase=1;  // one test case
  //  cin >> testCase ;
 while(testCase--)
        solve();  // my code

    return 0;
}