#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_ON(bit, i) (bit & (1LL << i))

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;
template<typename T> using VVVV = std::vector<std::vector<std::vector<std::vector<T>>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }
template<class T> inline std::vector<T> unique(std::vector<T> v) {
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    return v;
}

const int INF = 1 << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = { 0, 1, 0, -1 }, dx4 = { 1, 0, -1, 0 };    // 4近傍（右, 下, 左, 上）
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    while (true) {
        int N;
        cin >> N;
        if (N == 0) {
            break;
        }

        V<string> tmp;
        FOR(i, 0, N) {
            string S;
            cin >> S;
            tmp.emplace_back(S);
        }

        tmp = unique(tmp);

        V<string> v;
        FOR(i, 0, tmp.size()) {
            string s = tmp[i];
            bool ok = true;

            FOR(j, 0, tmp.size()) {
                string t = tmp[j];
                if (i == j) {
                    continue;
                }

                if (t.find(s) != string::npos) {
                    ok = false;
                }
            }
            if (ok) {
                v.emplace_back(s);
            }
        }
        VV<string> memo(v.size(), V<string>(v.size(), ""));
        FOR(i, 0, v.size()) {
            string s = v[i];
            FOR(j, 0, v.size()) {
                string t = v[j];

                int same = 0;
                for (int n = v[j].size(); n >= 0; --n) {

                    bool ok = true;
                    FOR(k, 0, n) {
                        if (s[s.size() - n + k] != t[k]) {
                            ok = false;
                            break;
                        }
                    }
                    if (ok) {
                        same = n;
                        break;
                    }
                }
                string ans = "";
                FOR(k, same, t.size()) {
                    ans += t[k];
                }
                memo[i][j] = ans;
            }
        }

        string ans = "";
        FOR(i, 0, 110) {
            ans += "z";
        }

        V<int> idx(v.size());
        iota(ALL(idx), 0);

        do {
            string t = v[idx[0]];
            FOR(i, 1, v.size()) {
                t += memo[idx[i - 1]][idx[i]];
                if (t.size() > ans.size()) {
                    break;
                }
            }

            if (t.size() == ans.size()) {
                ans = min(ans, t);
            }
            else if (t.size() < ans.size()) {
                ans = t;
            }
        } while(next_permutation(ALL(idx)));

        print(ans);
    }

    return 0;
}
