const
            f1='inversmodular.in';
            f2='inversmodular.out';
var
     a,b,x,y:longint;

procedure euclid(a,b:longint;var x,y:longint);
var x1,y1:longint;
 begin
   if b=0 then
    begin
     x:=1;
     y:=0;
    end
   else
    begin
     euclid(b,a mod b,x1,y1);
     x:=y1;
     y:=x1-(a div b)*y1;
    end;
 end;

begin
 assign(input,f1); reset(input);
 assign(output,f2); rewrite(output);
  readln(a,b);
  close(input);
      euclid(a,b,x,y);
       while x<0 do
          inc(x,b);
  write(x);
  close(output);
end.