nadesiko, 131 bytes

Result

WA

Duration

1150ms

Code [DL]

JS{{{
process.stdin.on('data',s=>{[h,w]=(''+s).split(`
`)
for(s=h;s-->0;)console.log("*"+(s>0&s<h-1?" ":"*").repeat(w-2)+"*")})
}}}

stdin

80
45

stdout

stderr

undefined:8
process.stdin.on('data',s=>{[h,w]=(''+s).split(`
                             ^

ReferenceError: h is not defined
    at Socket.process.stdin.on.s (eval at _run (/usr/lib/node_modules/nadesiko3/src/nako3.js:150:7), <anonymous>:8:30)
    at Socket.emit (events.js:182:13)
    at addChunk (_stream_readable.js:283:12)
    at readableAddChunk (_stream_readable.js:264:11)
    at Socket.Readable.push (_stream_readable.js:219:10)
    at Pipe.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)