#define _CRT_SECURE_NO_WARNINGS
//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
//#define int ll
//#define endl "\n"
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;
#define all(c) (c).begin(), (c).end()
#define loop(i,a,b) for(ll i=a; i<ll(b); i++)
#define rep(i,b) loop(i,0,b)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
template<class T> ostream & operator<<(ostream & os, vector<T> const &);
template<int n, class...T> typename enable_if<(n>=sizeof...(T))>::type _ot(ostream &, tuple<T...> const &){}
template<int n, class...T> typename enable_if<(n< sizeof...(T))>::type _ot(ostream & os, tuple<T...> const & t){ os << (n==0?"":" ") << get<n>(t); _ot<n+1>(os, t); }
template<class...T> ostream & operator<<(ostream & os, tuple<T...> const & t){ _ot<0>(os, t); return os; }
template<class T, class U> ostream & operator<<(ostream & os, pair<T,U> const & p){ return os << "(" << p.first << ", " << p.second << ") "; }
template<class T> ostream & operator<<(ostream & os, vector<T> const & v){ rep(i,v.size()) os << v[i] << (i+1==(int)v.size()?"":" "); return os; }
template<class T> inline bool chmax(T & x, T const & y){ return x<y ? x=y,true : false; }
template<class T> inline bool chmin(T & x, T const & y){ return x>y ? x=y,true : false; }
#ifdef DEBUG
#define dump(...) (cerr<<#__VA_ARGS__<<" = "<<mt(__VA_ARGS__)<<" ["<<__LINE__<<"]"<<endl)
#else
#define dump(...)
#endif
// ll const mod = 1000000007;
ll const inf = 1<<28;

int N;
vvi g;

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    while(cin >> N && N){
        vector<string> s(N);
        rep(i,N) cin >> s[i];
        sort(all(s));
        s.erase(unique(all(s)),s.end());
        N = s.size();
        rep(i,N)rep(j,N)if(i!=j){
            if(s[i].find(s[j])!=string::npos) s[j] = "~";
        }
        s.erase(remove(all(s),"~"),s.end());
        N = s.size();
        g.assign(N,vi(N,inf));
        rep(i,N)rep(j,N){
            if(i==j) continue;
            for(int k=min(s[i].size(),s[j].size()); k>=0; k--){
                auto a = max(s[i].begin(),s[i].end()-k);
                auto b = s[i].end();
                auto c = s[j].begin();
                auto d = min(s[j].begin()+k,s[j].end());
                if(b-a==d-c && equal(a,b,c)){
                    g[i][j] = k;
                    break;
                }
            }
        }

        vector<pair<int,vector<char>>> cand;
        vector<char> k(N);
        rep(i,N) k[i] = i;
        int m = inf;
        do{
            int l = s[k[0]].size();
            rep(i,N-1) l += s[k[i+1]].size() - g[k[i]][k[i+1]];
            m = min(l,m);
            if(l <= m) cand.eb(l,k);
        }while(next_permutation(all(k)));
        reverse(all(cand));
        string ans(1000,'~');
        dump(cand.size());
        rep(i,cand.size()){
            if(i!=0 && cand[i-1].first < cand[i-1].first) break;
            vector<char> & l = cand[i].second;
            string c = s[l[0]];
            rep(j,N-1) c += s[l[j+1]].substr(g[l[j]][l[j+1]]);
            ans = min(ans,c,[](string const & a, string const & b){
                    return a.size() != b.size() ? a.size() < b.size() : a < b;
                });
        }
        cout << ans << endl;
    }
}

Measured memory_bytes: 26884