program NSD2;

uses Crt;

var A, B : integer;

begin

 write('Zadej 1. cislo: '); read(A);

 write('Zadej 2. cislo: '); read(B);

 while (A<>0)and(B<>0) do

                  if A>B  then A:=A mod B   

                          else B:=B mod A;

 if A<>0   then writeln('NSD = ',A)

           else writeln('NSD = ',B);

 repeat until keypressed;

end.