node, 107 bytes

Result

AC

Duration

1230ms

Code [DL]

for([a,b]=(0+require('fs').readFileSync(i=0)).split`
`;i<a;)console.log(`*${'* '[i++>0&i<a].repeat(b-2)}*`)

stdin

18
36

stdout

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

stderr