h2. Restricţii

* $1 ≤ N ≤ 500.000$

* $1 ≤ N ≤ 200.000$

* Se considera subsecventa a unui sir $a{~1~}$, $a{~2~}$, ..., $a{~N~}$ sirul $a{~i{~1~}~}$, $a{~i{~2~}~}$, ... $a{~i{~k~}~}$, cu proprietatea ca $1 ≤ i{~1~}$ ≤ $i{~2~}$ ≤ ... ≤ $i{~k~} ≤ N$
* Doua subsecvente $a{~i{~1~}~}$, $a{~i{~2~}~}$, ... $a{~i{~k~}~}$ si $a{~j{~1~}~}$, $a{~j{~2~}~}$, $a{~j{~l~}~}$ se considera distincte, daca $l ≠ k$, sau exista $t ≤ k$, astfel incat $a{~i{~t~}~} ≠ a{~j{~t~}~}$