csharp, 157 bytes

Result

WA

Duration

1360ms

Code [DL]

using C=System.Console;class Y{static int R=>int.Parse(C.ReadLine());static void Main(){for(int a=R,i=0;i<a;)C.Write("*"+"*\n".PadLeft(a,++i%a>1?' ':'*'));}}

stdin

30
23

stdout

******************************
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
*                            *
******************************

stderr