var x,a,b:longint;
     f,g:text;

 function cmmdc (a,b:longint):longint;
          begin
           repeat
            if a>b then a:=a-b
             else if b>a then b:=b-a;
           until a=b;
            cmmdc:=a;
          end;

 begin
  assign(f,'cmmdc.in');reset(f);
  assign(g,'cmmdc.out');rewrite(g);
  read(f,a,b);
  x:=cmmdc(a,b);
  write(g,a);
  close(f); close(g);
 end.