# include <iostream>
# include <algorithm>
using namespace std;
int main(){
    int N = 0;
    cin>>N;
    cout<<endl;
    int A[N];
    for (int i = 0; i < N; i++) {
        cin>>A[i];
    }
    sort(A, A+N);
    int mid = N/2;
    for (int i = 0; i < mid ; i++) {
        cout<<A[i]<< " ";
    }
     for (int i = mid - 1; i >= 0; i--) {
        cout<<A[i]<< " ";
    }
    cout<<endl;
     for (int i = mid ; i < N; i++) {
        cout<<A[i]<< " ";
    }
        for (int i = N - 1; i >= mid; i--) {
            cout<<A[i]<< " ";
        }
 
    return 0;
}

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