{-(Program
  (If
    (Identifier)
    (ExpressionStatements
      (Identifier))
    (If
      (Identifier)
      (ExpressionStatements
        (ExpressionStatements
          (Identifier)))
      (If
        (Identifier)
        (ExpressionStatements
          (Identifier))
        (If
          (Identifier)
          (ExpressionStatements
            (ExpressionStatements
              (Identifier)))
          (ExpressionStatements
            (Identifier)))))))-}