How to check count files inside Res is equal 1 or not ?

Question

I work on c# app I face Issue I need to check count of files inside result equal 1 or not ?

 

when I use count res.count count not display AS Int license .

 

so by any way I need to check on result variable if returned one file or bigger than 1

 

so How to do that Please ?

static void Main(string[] args) {
 DataTable dataTable = GetData();
 var res = from row in dataTable.AsEnumerable()
 group row by row["Files"] into g
 select g;
 if (res.count == 1) {} else {}
}
public static DataTable GetData() {
 DataTable dataTable = new DataTable();
 dataTable.Columns.Add("PartId", typeof(int));
 dataTable.Columns.Add("Company", typeof(string));
 dataTable.Columns.Add("Files", typeof(string));
 dataTable.Columns.Add("Tab", typeof(string));
 dataTable.Columns.Add("Module", typeof(int));

 dataTable.Rows.Add(1222, "micro", "Abc", "source", 1);
 dataTable.Rows.Add(1321, "silicon", "Abc", "Types", 3);
 dataTable.Rows.Add(1444, "cd2", "AutoD", "Rev", 10);
 dataTable.Rows.Add(1321, "cd3", "AutoD", "source", 11);
 dataTable.Rows.Add(1541, "mtvscro", "AutoD", "Rev", 12);
 dataTable.Rows.Add(9811, "tvs2", "Mog", "Dal", 6);
 dataTable.Rows.Add(1901, "tvs3", "Mog", "Mondo", 6);
 dataTable.Rows.Add(2111, "toyo", "Mog", "Pingo", 7);
 return dataTable;
}