#include <iostream> #include <vector> #include<algorithm> using namespace std; bool comparation(string a,string b) { return (a+b)<(b+a); } int main() { int i=0; int n=0; while(cin>>n) { vector <string> a; for(i=0;i<n;i++) { string b; cin>>b; a.push_back(b); } sort(a.begin(),a.end(),comparation); string ans; for(i=n-1;i>=0;i--) { ans+=a[i]; } cout<<ans<<endl; } return 0; }