Program Fractii;
var fi, fo : text;
    i,j,nr:longint;
    n,q:qword;
Function CMMDC(a,b : longint):longint;
begin
     if a mod b = 0 then cmmdc:=b
                     else cmmdc:=cmmdc(b,a mod b);
end;
begin
     assign(fi,'frac.in'); reset(fi); readln(fi,n,q); close(fi);
     assign(fo,'frac.out'); rewrite(fo); j:=n; i:=0;
     while q<>0 do  begin i:=i+1;
                          if i>=j then nr:=CMMDC(i,j)
                                  else nr:=CMMDC(j,i);
                          if nr=1 then q:=q-1;
                    end;
     write(fo,i); close(fo);
end.