var a:array[1..20]of longint; s:array[1..20]of string; i,j,n:longint; t:string;begin read(n); for i:=1 to n do begin read(a[i]); str(a[i],s[i]); end; for i:=1 to n-1 do for j:=i+1 to n do if s[i]+s[j]<s[j]+s[i] then begin t:=s[i]; s[i]:=s[j]; s[j]:=t; end; for i:=1 to n do write(s[i]);end.