Program So_bac_thang;

Var i,n1,n2: integer;

Function BT(n:integer):Boolean;

Var ok: boolean;

so:byte;

Begin

ok:=true;

While n>=10 do

Begin

so:=n mod 10;

n:=n div 10;

if so < (n mod 10) then ok:=ok and false;

End;

BT:=ok;

End;

Begin

Write('Nhap so n1: ');Readln(n1);

Write('Nhap so n2: ');Readln(n2);

For i:= n1 to n2 do if BT(i) then Write(i:4);

Readln

End.

uses crt;
var s:string; i,kt,k:longint;
begin
clrscr;
   write('n=');readln(s);
   for i:=1 to length(s) do if s[i]='.' then k:=i;
   delete(s,1,k);
   i:=length(s);
   if (k<>0)and(length(s)>1) then begin while s[i]='0' do begin delete(s,i,1); dec(I); end;
   for i:=2 to length(s) do if s[i]<s[i-1] then kt:=1; end;
   if (k=0)or(length(s)<=1)or(kt=1) then writeln('Day khong la so bac thang') else writeln('Day la so bac thang');
readln
end.