function prim(m,n:integer):boolean;
    var i,min:integer;
    begin
    prim:=TRUE;
      if m>n then min:=n else min:=m;
      for i:=2 to min do if (m mod i=0) and (n mod i=0) then prim:=FALSE;
      if m=n then prim:=FALSE;

    end;

var n,p,i,c:longint;

begin

assign(input,'frac.in'); reset(input);
assign(output,'frac.out'); rewrite(output);

readln(n,p);
i:=0;
repeat
  i:=i+1;
  if prim(i,n) then c:=c+1;

until c=p;
     write(i);

     close(input);
     close(output);

     end.