#include <bits/stdc++.h>
#define INF 1e9
#define LGMAX 300008

using namespace std;
ifstream fin ("adn.in");
ofstream fout ("adn.out");

int n;
int len[LGMAX], cost[20][20], dp[1<<20][20], pre[1<<20][20];
bool e_inclus[20];
string adn[20];
vector <int> sol;

void citire();
int KMP(string a, string b);
bool caut_subsir(string a, string b);
void create_graph();
void ciclu_hamiltonian();

int main()
{
    citire();
    create_graph();
    ciclu_hamiltonian();
    return 0;
}

void citire()
{
    fin >> n;
    for (int i = 0; i < n; i++)
        fin >> adn[i];
}

int KMP(string a, string b)
{
    string s = b + a;
    for (int i = 1; i < s.size(); i++)
    {
        int j = len[i-1];
        while (j > 0 && s[i] != s[j])
            j = len[j-1];
        if (s[i] == s[j])
            j++;
        len[i] = j;
    }

    return len[s.size()-1];
}

bool caut_subsir(string a, string b)
{
    if (b.size() > a.size())
        return 0;
    string s = b + a;
    for (int i = 1; i < s.size(); i++)
    {
        int j = len[i-1];
        while (j > 0 && s[i] != s[j])
            j = len[j-1];
        if (s[i] == s[j])
            j++;
        len[i] = j;
        if (len[i] == b.size())
            return 1;
    }
    return 0;
}

void create_graph()
{
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (i != j)
            {
                if (e_inclus[j])
                    continue;
                e_inclus[j] = caut_subsir(adn[i], adn[j]);
                if (e_inclus[j])
                {
                    if (adn[i].size() == adn[j].size())
                    {
                        e_inclus[min(i, j)] = 0;
                        e_inclus[max(i, j)] = 1;
                    }
                    continue;
                }
                int c = KMP(adn[i], adn[j]);
                cost[i][j] = c;
            }
}

void ciclu_hamiltonian()
{
    int maxim = (1 << n);
    for (int mask = 0; mask < maxim; mask++)
        for (int j = 0; j < n; j++)
            dp[mask][j] = INF;

    for (int j = 0; j < n; j++)
        dp[1<<j][j] = adn[j].size();

    for (int mask = 0; mask < maxim; mask++)
        for (int j = 0; j < n; j++)
        {
            if (e_inclus[j])
            {
                for (int i = 0; i < n; i++)
                    if (i != j)
                    {
                        if (dp[mask][j] > dp[mask ^ (1<<j)][i])
                        {
                            dp[mask][j] = dp[mask ^ (1<<j)][i];
                            pre[mask][j] = i;
                        }
                    }
                continue;
            }
            if (!e_inclus[j] && (mask & (1 << j)))
                for (int k = 0; k < n; k++)
                    if (k != j && (mask & (1 << k)))
                        {
                            int sz = adn[j].size();
                            if (dp[mask ^ (1<<j)][k] + sz - cost[k][j] < dp[mask][j])
                            {
                               dp[mask][j]  = dp[mask ^ (1<<j)][k] + sz - cost[k][j];
                               pre[mask][j] = k;
                            }
                        }
        }
    int minim = INF;
    maxim--;
    int poz;
    for (int i = 0; i < n; i++)
        if (dp[maxim][i] < minim)
        {
            minim = dp[maxim][i];
            poz = i;
        }
    if (!e_inclus[poz])
        sol.push_back(poz);
    for (int i = 1; i < n; i++)
    {
        int copie = poz;
        poz = pre[maxim][copie];
        maxim = maxim ^ (1 << copie);
        if (!e_inclus[poz])
            sol.push_back(poz);
    }

    //for (int i = sol.size()-1; i >= 0; i--)
        //fout << sol[i] << ' ';
    fout << adn[sol[sol.size()-1]];
    for (int i = sol.size()-2; i >= 0; i--)
    {
        for (int j = cost[sol[i+1]][sol[i]]; j < adn[sol[i]].size(); j++)
            fout << adn[sol[i]][j];
    }
}