program gls;
var n,p,k,a,max:longint;
ss:array[1..10000]of longint;
st:array[1..10000]of longint;
sw:array[1..10000]of longint;
f,g:text;
    procedure swapp(w:longint);
    begin
       if w<>k then
       begin inc(p);
            swapp(ss[w]);
       end;
    end;
     function gcd(a,b:longint):longint;
      var
      t:longint;
      begin
      while a mod b <> 0 do
       begin
       t:=a mod b;
       a:=b;
       b:=t;
       end;
       gcd:=b;
      end;
      function lcm(a,b:longint):longint;
       begin
       lcm:= a*b div gcd(a,b);
       end;

begin
  assign(f,'officer.in');
  reset(f);
  assign(g,'officer.out');
  rewrite(g);
  readln(f,n);
  for k:=1 to n do
  begin readln(f,a);
     ss[k]:=a;
  end;

  for k:=1 to n do
  begin
     p:=0;
    swapp(ss[k]);
    st[k]:=p+1;
  end;
  max:=st[1];
  for k:=1 to k do
   max:=lcm(max,st[k]);

writeln(g,max);
close(f);close(g);
end.