#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
#include<vector>
#include<map>
#include<unordered_map>
#include<cstdlib>
using namespace std;
typedef long long LL;
const LL N=100010,MOD=998224353,INF=0x7f7f7f7f;
string s[N];
int cnt;
// bool cmp(string& x,string& y){
// string u=x+y,v=y+x;
// return u<v;
// }bool cmp(string& x,string& y){int lx=x.size(),ly=y.size();int sz=max(lx,ly);for(int i=0;i<sz;i++){if(i>lx-1){string u = x+y,v = y+x;for(int j=0;j<sz+lx;j++){if(u[j]<v[j]){return 1;}else if(u[j]>v[j]){return 0;}}return 1;}else if(i>ly-1){string u = x+y,v = y+x;for(int j=0;j<sz+ly;j++){if(u[j]<v[j]){return 1;}else if(u[j]>v[j]){return 0;}}return 1;}else if(x[i]<y[i]){return 1;}else if(x[i]>y[i]){return 0;}}return 1;
}int main(){ios::sync_with_stdio(false),cin.tie(0);cnt=0;int n;cin>>n;for(int i=0;i<n;i++){string ss;cin>>ss;if(ss.size()>1){s[cnt]="";int idx=-1;for(int j=1;j<ss.size();j++){if(ss[j-1]>ss[j]){idx=j-1;break;}}if(idx==-1){idx=ss.size()-1;}for(int j=0;j<ss.size();j++){if(j!=idx){s[cnt]+=ss[j];}}cnt++;}// s[cnt++]=ss;}sort(s,s+cnt,cmp);for(int i=0;i<cnt;i++){cout<<s[i];}return 0;
}