#include <iostream>
#include <vector>
#include <string>
using namespace std;

#define N 15
int n;
string ss[N];
string g[N][N];
int dp[1<<N][N+1],next[1<<N][N+1];

string connect(string& s, string& t) {
  for (int i=0;i<(int)s.size();++i) {
    int ok=1;
    for (int j=0;i+j<(int)s.size();++j) {
      if (s[i+j]!=t[j]) {
	ok=0;
	break;
      }
    }
    if (ok) return t.substr(s.size()-i);
  }
  return t;
}

int solve(int used, int pos){
  if (used==(1<<n)-1) return 0;
  int& res=dp[used][pos];
  if (res!=-1) return res;
  res=INT_MAX;
  for (int npos=0;npos<n;++npos) {
    if (used&(1<<npos)) continue;
    int r=g[pos][npos].size()+solve(used|(1<<npos),npos);
    if (r<res) {
      res=r;
      next[used][pos]=npos;
    } else if (r==res&&g[pos][npos]<g[pos][next[used][pos]]) {
      next[used][pos]=npos;
    }
  }
  return res;
}

string solve2(int used, int pos) {
  if (used==(1<<n)-1) return "";
  int npos=next[used][pos];
  return g[pos][npos]+solve2(used|(1<<npos),npos);
}

int main() {
  while(cin>>n,n) {
    for (int i=0;i<n;++i) cin>>ss[i];
    for (int i=0;i<n;++i) {
      for (int j=0;j<n;++j)
	if (i!=j&&ss[j].find(ss[i])!=string::npos) {
	  swap(ss[i--],ss[(n--)-1]);
	  break;
	}
    }

    for (int i=0;i<n;++i)
      for (int j=0;j<n;++j) 
	if (i!=j) 
	  g[i][j]=connect(ss[i],ss[j]);
    for (int i=0;i<n;++i) g[n][i]=ss[i];

    memset(dp,-1,sizeof(dp));
    solve(0,n);
    string ans=solve2(0,n);
    cout<<ans<<endl;
  }
}