Delete Sidechat markers

{
  private "_a";
  _a = toArray _x;
  _a resize 15;
  if (toString _a == "_USER_DEFINED #") then {
    _b = _x splitString "/";
    _c = _b select 2;
    if(_c == 0 || _c == 1) then {
      deleteMarker _x;
    };
  };
} forEach allMapMarkers;