enumeration_io: get error

["Gino POLIDO" <gino.polido@wanadoo.fr>]

Look at this. If you get "*" or another no alpha numeric character, there is
a loop and it raises a storagr_error.
How to do?

Thks

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package Mytype is

type Tmytype is (a,b,c);

end Mytype;

with Mytype;
with ada.text_io;

package Enumeration_Tmytype is new
ada.text_io.enumeration_io(Mytype.Tmytype);

with Mytype;
with Enumeration_Tmytype;
with ada.text_io;

procedure tests is
 input:Mytype.Tmytype;
begin
 for i in 1..4 loop
  ada.text_io.put("Choose(a,b, or c):");
  enumeration_Tmytype.get(input);
 end loop;

exception
 when others =>
  tests;
end tests;