Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 1)
    ExpressionList (children 1)
     Function CAST (alias c) (children 1)
      ExpressionList (children 2)
       Function plus (children 1)
        ExpressionList (children 2)
         Function plus (children 1)
          ExpressionList (children 2)
           Function plus (children 1)
            ExpressionList (children 2)
             Function plus (children 1)
              ExpressionList (children 2)
               Literal UInt64_0
               Literal UInt64_1
             Literal UInt64_2
           Literal UInt64_3
         Literal UInt64_4
       Literal \'Date\'
