SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier source.count (alias count)
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias source) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 3)
          ExpressionList (children 2)
           Function count (alias count) (children 1)
            ExpressionList (children 1)
             Asterisk
           Identifier key
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             Function numbers (children 1)
              ExpressionList (children 1)
               Literal UInt64_10
          ExpressionList (children 1)
           Function modulo (alias key) (children 1)
            ExpressionList (children 2)
             Identifier number
             Literal UInt64_2
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier system.one (alias r)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier source.key
        Identifier r.dummy
