#include <fstream>
#include <algorithm>
#include <cstring>
#include <tuple>

using namespace std;

ifstream in("adn.in");
ofstream out("adn.out");

const int MAX_N = 18;
const int MAX_LEN = 30000;
const int MAX_CFG = 1 << MAX_N;
const int INF = 0x7fffffff;

int n;
int R[MAX_CFG][1 + MAX_N];
int D[MAX_CFG][1 + MAX_N];
int C[1 + MAX_N][1 + MAX_N];
char S[1 + MAX_N][MAX_LEN + 5];
int P[5 + MAX_LEN];
int L[1 + MAX_N];
bool DEL[1 + MAX_N];

int substring(int u, int v) {
    int i, q, lu, lv;

    lu = strlen(S[u] + 1);
    lv = strlen(S[v] + 1);

    if(lu > lv) {
        swap(u, v);
        swap(lu, lv);
    }

    memset(P, 0, sizeof(P));
    for(i = 2, q = 0; i <= lu; i++) {
        while(q > 0 && S[u][q + 1] != S[u][i]) q = P[q];
        if(S[u][q + 1] == S[u][i]) q++;
        P[i] = q;
    }
    for(i = 1, q = 0; i <= lv; i++) {
        while(q > 0 && S[u][q + 1] != S[v][i]) q = P[q];
        if(S[u][q + 1] == S[v][i]) q++;
        if(q == lu) {
            return u;
        }
    }

    return 0;
}

int getEdgeCost(int u, int v) {
    int lu = L[u], lv = L[v], i, q;

    memset(P, 0, sizeof(P));

    for(i = 2, q = 0; i <= lv; i++) {
        while(q > 0 && S[v][q + 1] != S[v][i]) q = P[q];
        if(S[v][q + 1] == S[v][i]) q++;
        P[i] = q;
    }

    for(i = 1, q = 0; i <= lu; i++) {
        while(q > 0 && S[v][q + 1] != S[u][i]) q = P[q];
        if(S[v][q + 1] == S[u][i]) q++;
    }

    return q;
}

void printSol(int cfg, int last) {
    if((cfg & (cfg - 1)) == 0) {
        out << S[last + 1] + 1;
    }
    else {
        printSol(cfg - (1 << last), R[cfg][last]);
        out << S[last + 1] + 1 + C[R[cfg][last]][last];
    }
}

int main() {
    int i, j, k, cfg, last, len;

    in >> n;
    for(i = 1; i <= n; i++) in >> (S[i] + 1);

    for(i = 1; i <= n; i++) {
        for(j = i + 1; j <= n; j++) {
            DEL[substring(i, j)] = true;
        }
    }
    for(i = 0, j = 1; j <= n; j++) {
        if(!DEL[j]) {
            i++;
            strcpy(S[i] + 1, S[j] + 1);
        }
    }

    n = i;
    for(i = 1; i <= n; i++) {
        L[i] = strlen(S[i] + 1);
    }

    for(i = 1; i <= n; i++) {
        for(j = 1; j <= n; j++) {
            if(i != j) {
                C[i - 1][j - 1] = getEdgeCost(i, j);
            }
        }
    }

    for(i = 1; i < (1 << n); i++) {
        for(j = 0; j < n; j++) {
            D[i][j] = INF;
            R[i][j] = 0;
        }
    }
    for(i = 0; i < n; i++) {
        D[1 << i][i] = L[i + 1];
        R[i][j] = 0;
    }

    for(i = 1; i < (1 << n); i++) {
        for(j = 0; j < n; j++) {
            if(i & (1 << j)) {
                cfg = i - (1 << j);
                for(k = 0; k < n; k++) {
                    if(cfg & (1 << k)) {
                        if(D[i][j] > D[cfg][k] + L[j + 1] - C[k][j]) {
                            D[i][j] = D[cfg][k] + L[j + 1] - C[k][j];
                            R[i][j] = k;
                        }
                    }
                }
            }
        }
    }

    for(i = 0, len = INF; i < n; i++) {
        if(len > D[(1 << n) - 1][i]) {
            len = D[(1 << n) - 1][i];
            last = i;
        }
    }

    printSol((1 << n) - 1, last);
    return 0;
}