var fi,fo:text;  
    function cmmdc(a,b:longint):longint;  
    begin  
      if b=0 then cmmdc:=a  
       else cmmdc:=cmmdc(b,a mod b);  
     end;  
     var a,b:longint;  
     begin  
     assign(fi,'euclid2.in'); reset(fi);  
     assign(fo,'euclid2.out'); rewrite(fo);  
     read(fi,a,b);  
     writeln(fo,cmmdc(a,b));  
     close(fi);  
     close(fo);  
   end.