var head,vet,next,s,b,stack,low,dfn,flag:array[..]of longint;

     n,i,ans,tot,id,top,time,x:longint;

 procedure add(a,b:longint);

 begin

  inc(tot);

  next[tot]:=head[a];

  vet[tot]:=b;

  head[a]:=tot;

 end;

 function min(x,y:longint):longint;

 begin

  if x<y then exit(x);

  exit(y);

 end;

 procedure dfs(u:longint);

 var e,v:longint;

 begin

  flag[u]:=;

  inc(top); stack[top]:=u;

  inc(time); dfn[u]:=time; low[u]:=time;

  e:=head[u];

  while e<> do

  begin

   v:=vet[e];

   if flag[v]= then

   begin

    dfs(v);

    low[u]:=min(low[u],low[v]);

   end

    else if s[v]= then low[u]:=min(low[u],low[v]);

   e:=next[e];

  end;

  if low[u]=dfn[u] then

  begin

   inc(id); s[u]:=id; inc(b[id]);

   while (top>)and(stack[top]<>u) do

   begin

    s[stack[top]]:=id;

    inc(b[id]);

    stack[top]:=;

    dec(top);

   end;

   stack[top]:=;

   dec(top);

  end;

 end;

 begin

  //assign(input,'1.in'); reset(input);

  //assign(output,'1.out'); rewrite(output);

  readln(n);

  for i:= to n do

  begin

   read(x);

   add(i,x);

  end;

  for i:= to n do

   if flag[i]= then dfs(i);

  ans:=n;

  for i:= to id do

   if (b[i]>)and(b[i]<ans) then ans:=b[i];

  if n= then writeln()

   else writeln(ans);

  //close(input);

  //close(output);

 end.