[{"_id":ObjectId("5b107bec1d2952d0da9046e1"),"title":"A Million Ways to Die in the West","year":2014,"rated":"R","runtime":116,"countries":["USA"],"genres":["Comedy","Western"],"director":"Seth MacFarlane, TG, JN","writers":["Seth MacFarlane","Alec Sulkin","Wellesley Wild"],"actors":["Seth MacFarlane","Charlize Theron","Amanda Seyfried","Liam Neeson"],"plot":"As a cowardly farmer begins to fall for the mysterious new woman in town, he must put his new-found courage to the test when her husband, a notorious gun-slinger, announces his arrival.","poster":"http://ia.media-imdb.com/images/M/MV5BMTQ0NDcyNjg0MV5BMl5BanBnXkFtZTgwMzk4NTA4MTE@._V1_SX300.jpg","imdb":{"id":"tt2557490","rating":6.1,"votes":126592},"tomato":{"meter":33,"image":"rotten","rating":4.9,"reviews":188,"fresh":62,"consensus":"While it offers a few laughs and boasts a talented cast, Seth MacFarlane's overlong, aimless A Million Ways to Die in the West is a disappointingly scattershot affair.","userMeter":40,"userRating":3,"userReviews":62945},"metacritic":44,"awards":{"wins":0,"nominations":6,"text":"6 nominations."},"type":"movie"},{"_id":ObjectId("5b107bec1d2952d0da9046e0"),"title":"Once Upon a Time in the West","year":1968,"rated":"PG-13","runtime":175,"countries":["Italy","USA","Spain"],"genres":["Western"],"director":"Sergio Leone, TG","writers":["Sergio Donati","Sergio Leone","Dario Argento","Bernardo Bertolucci","Sergio Leone"],"actors":["Claudia Cardinale","Henry Fonda","Jason Robards","Charles Bronson"],"plot":"Epic story of a mysterious stranger with a harmonica who joins forces with a notorious desperado to protect a beautiful widow from a ruthless assassin working for the railroad.","poster":"http://ia.media-imdb.com/images/M/MV5BMTEyODQzNDkzNjVeQTJeQWpwZ15BbWU4MDgyODk1NDEx._V1_SX300.jpg","imdb":{"id":"tt0064116","rating":8.6,"votes":201283},"tomato":{"meter":98,"image":"certified","rating":9,"reviews":54,"fresh":53,"consensus":"A landmark Sergio Leone spaghetti western masterpiece featuring a classic Morricone score.","userMeter":95,"userRating":4.3,"userReviews":64006},"metacritic":80,"awards":{"wins":4,"nominations":5,"text":"4 wins & 5 nominations."},"type":"movie"}]

db.collection.aggregate([{$match:{director:{$ne:null}}},{$set:{directorsCount:{$size:{$split:["$director",","]}}}},{$group:{_id:"$directorsCount",value:{$sum:1}}}])