public function store(Request $request) {
        $rule = [
            'nama_kelas' => 'required',
            'jurusan' => 'required',
            'lokasi_ruangan' => 'required|min:2',
            'nama_walikelas' => 'required',
        ];
        $this->validate($request, $rule);

        $input = $request->all();
        unset($input['_token']);
        $status = \DB::table('t_kelas')->insert($input);

        if ($status) {
            return redirect('/tugas')->with('success', 'Data berhasil ditambahkan');
        } else {
            return redirect('/kelas/create')->with('error', 'Data gagal ditambahkan');
        }