mongoDb field count query - mongodb

Question

I have MongoDB collection with the following format:
{
"_id" : ObjectId("5b6b112d1bbd972848b97df4"),
"Game" : [
{
"City" : "Nizhny Novgorod",
"T2N" : "Costa Rica",
"T1N" : "Switzerland",
"ST" : "Nizhny Novgorod Stadium",
"T1S" : "2",
"Date" : "6/27/2018",
"T2S" : "2"
},
{
"City" : "Kaliningrad",
"T2N" : "Serbia",
"T1N" : "Switzerland",
"ST" : "Kaliningrad Stadium",
"T1S" : "2",
"Date" : "6/22/2018",
"T2S" : "1"
},
{
"City" : "Rostov-on-Don",
"T2N" : "Brazil",
"T1N" : "Switzerland",
"ST" : "Rostov Arena",
"T1S" : "1",
"Date" : "6/17/2018",
"T2S" : "1"
},
{
"City" : "Saint Petersburg",
"T2N" : "Sweden",
"T1N" : "Switzerland",
"ST" : "Saint Petersburg Stadium",
"T1S" : "0",
"Date" : "7/3/2018",
"T2S" : "1"
}
],
"team" : "Switzerland"
}
How can I get the total of T1S and Total of T2S for each team?
I am trying the following query
db.test3.aggregate([{$match:{}},{$group:{_id:"$team", goalScored:{$sum:"Game.T1S"},goalConceaded:{$sum:"Game.T2S"}}}])
But I am getting the following output:
{ "_id" : "Tunisia", "goalScored" : 0, "goalConceaded" : 0 }
{ "_id" : "Uruguay", "goalScored" : 0, "goalConceaded" : 0 }
{ "_id" : "Egypt", "goalScored" : 0, "goalConceaded" : 0 }
In the above, the goalscored and goalconceded are always 0 which is not expected. Any help is appreciated.