VAR
 D1,D2,GCD:Word;

Procedure Order(a,b:Word; var a1:Word; var b1:word);
Begin
 if a>b then
  begin
   a1:=a;
   b1:=b;
  end
 else
  begin
   a1:=b;
   b1:=a;
  end;
End;

Function Evklid(e1,e2:Word):Word;
Var
 m,c1,c2:Word;
Begin
 c1:=e1;
 c2:=e2;
 Repeat
  m:=c1 mod c2;
  c1:=c2;
  c2:=m;
 Until m=0;
 Evklid:=c1;
End;

BEGIN
 Write('First number: ');
 Readln(D1);
 Write('Second number: ');
 Readln(D2);
 Order(D1,D2,D1,D2);
 GCD:=Evklid(D1,D2);
 Writeln('Greatest Common Divisor = ',GCD);
 IF GCD>1 then
  Repeat
   D1:=GCD;
   Write('Next number (0 to quit): ');
   Readln(D2);
   If D2>0 then
    Begin
     Order(D1,D2,D1,D2);
     GCD:=Evklid(D1,D2);
     Writeln('Greatest Common Divisor = ',GCD);
    End;
  Until (D2=0) or (GCD=1);
 If GCD=1 then
  begin
   Writeln('Finished: GCD=1');
   Readln
  end;
END.