Destroy the Monster
/

## Very-Easy

Problem
Editorial
Analytics

Erza is a fearless Warrior of her guild. She is fighting a monster with Power P. She is using her special armour which helps her to defeat her enemy easily. With each attack the power of her attack increases by X amount. But after $i^{th}$ attack, she has to wait for i seconds to recharge her armour. Initial power of her attack is X.

Each attack takes 1 second. The enemy is defeated when its power reduces to 0 or below.

After every attack, the Power of monster reduces by the power of attack.

How much time does she takes defeating the monster?

Constraints:-
1 ≤ X ≤ 10
1 ≤ P$10^{9}$

Input Format:-
Single line consisting of 2 space-separated integers - P X

Output Format:-
Time taken by Erza to defeat the monster.

SAMPLE INPUT
8 3
SAMPLE OUTPUT
3
Time Limit: 1.0 sec(s) for each input file.
Memory Limit: 256 MB
Source Limit: 1024 KB

## This Problem was Asked in

Initializing Code Editor...

?