db.cities.findOne({_id:ObjectId("64a47c1447972c5696cb0765")})
  
   db.cities.updateMany(
  {_id:ObjectId("64a47c1447972c5696cb0765")}, // Filtro vacío para actualizar todos los documentos
  {
    $pull: {
      "itineraries": "64efc056590b86b1be2cdd1e"
    }
  }
)
   db.cities.updateMany(
  {_id:ObjectId("64a47c1447972c5696cb0765")}, // Filtro vacío para actualizar todos los documentos
  {
    $push: {
      "itineraries": "64efc056590b86b1be2cdd1e"
    }
  }
)
   db.getCollection("cities").updateMany({_id:ObjectId("64a47c1447972c5696cb0765")},
{$push:{"itineraries":"64efc056590b86b1be2cdd1e"}})