[{"_id":"0","timestamp":160000},{"_id":"00","timestamp":160000},{"_id":"000","timestamp":150000},]

db.collection.aggregate([{"$sort":{"timestamp":-1}},{"$limit":1},{"$lookup":{"from":"collection","localField":"timestamp","foreignField":"timestamp","as":"topTimeStamp"}},{"$project":{"_id":0,"result":"$topTimeStamp"}},])