unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Label1: TLabel;
    Panel1: TPanel;
    Label2: TLabel;
    Edit1: TEdit;
    Label3: TLabel;
    procedure Edit1Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
procedure fact(m:integer;var s:integer);
var i:integer;
begin
   s:=0;
   i:=2;
   while(i<=sqrt(m))and(s=0)do
       if m mod i=0 then s:=1 else i:=i+1;
end;

procedure TForm1.Edit1Change(Sender: TObject);
var a,b,n,s,c:integer;
begin
a:=strtoint(edit1.text);
b:=3;
while b<=a do
 begin
  fact(b,s);
  if s=0 then
   begin
     c:=a-b;
     fact(c,s);
     if s=0 then
       break;
   end;
   b:=b+1;
 end;
 label3.Caption:=format('%d=%d+%d',[a,b,c]);
 
end;

end.