package main

import (
	"fmt"
)

func main() {
	var N, R, C int
	fmt.Scan(&N)
	for cid := 1; cid <= N; cid++ {
		fmt.Scan(&R, &C)
		grid := make([]string, R+2)
		wall := make([]byte, C+2)
		for i := range wall {
			wall[i] = '#'
		}
		grid[0], grid[R+1] = string(wall), string(wall)
		for i := 1; i <= R; i++ {
			fmt.Scan(&grid[i])
			grid[i] = "#" + grid[i] + "#"
		}
	}
}