 <div class="input-group-prepend">
                    <button type="button" class="btn btn-danger">Action</button>
                  </div>
                  <!-- /btn-group -->
                  <input type="text" class="form-control">
                </div>
                <!-- /input-group -->
                <strong>Flat</strong>
                <div class="input-group mb-3">
                  <input type="text" class="form-control rounded-0">
                  <span class="input-group-append">
       