using C=System.Console;class P{static void Main(){string o="[",n=C.ReadLine(),m;for(int i=0,j;""+i++!=n;o+="]")for(o+=i>1?", [":o,j=0,m=C.ReadLine();""+j++!=m;)o+=(j>1?", ":"")+C.ReadLine();C.Write(o+"]");}}