public function update(Semester $semesters, validationRequest $request, $sid)
 {
     $Semester = $semesters->where("id", $sid)->first();
     $Semester->name = $request->input('name');
     $Semester->start_at = $request->input('start_at');
     $Semester->finish_at = $request->input('finish_at');
     $Semester->active = $request->has('active') ? request('active') : 0;
     if ($Semester->active) {
         //update set all semester not active
         $all_semesters = new Semester();
         $all_semesters->update(['active' => 0]);
     }
     $Semester->save();
     $yid = $Semester->academycycle_year_id;
     return redirect()->route('ac.semesters.index', compact('semester', 'yid'));
 }