#include <iostream>

using namespace std;


int fr[10] = {5,7,2,4,5,8,9,12,6,4};
int fr2[10];
int cif=-1;
int main()
{
    for(int i=0; i<=9; i++) fr2[i]=fr[i];
    for(int i=8; i>=2; i-=2)
    if (fr[i]>1) {
        cif = i;
        fr[i]-=2;
        break;
    }
    if (cif==-1) {cout << "nu mere"; return 0;};

    cout << cif;
    for(int i=9; i>=0; i--)
    {
        while (fr[i]>=2)
        {
            fr[i]-=2;
            cout << i;
        }
    }
    for(int i=9; i>=0; i--)
    {
        if (fr[i]){
            cout << i;
            break;
        }
    }

    for(int i=0; i<=9; i++)
    {
        while (fr2[i]>=2)
        {
            fr2[i]-=2;
            cout << i;
        }
    }
    cout << cif;
    return 0;
}