Synchronize array with simultaneous access via Photon Network RPC

Hi!

I have list with several items

  var list = new List<int>();
  list.Add(1);
  list.Add(2);
  list.Add(3);
  list.Add(4);

Each player can take item from it, this done locally, not via rpc. When player take item, rpc sended to other players to remove item from list.

 RemoveItemFromList(itemId);
 _photonView.RPC("RemoveItem", PhotonTargets.Others, item.Id);
 
 [RPC]
 private void RemoveItem(int itemId)
 {
    RemoveItemFromList(itemId);
 }
 
 private void RemoveItemFromList(int itemId)
 {
    var item = list.First(x=>x == itemId);
    list.Remove(item);
 }

It's working normal, but when several players get items simultaneously i have an error. Because two players can hit the same item. How can i sync them? I am using Photon Cloud.