SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Function count (children 1) ExpressionList TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) Subquery (alias l) (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Literal UInt64_1 (alias a) TablesInSelectQueryElement (children 2) TableExpression (children 1) Subquery (alias r) (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Literal UInt64_2 (alias a) TableJoin (children 1) ExpressionList (children 1) Identifier a