Time Is the Best Healer

After getting his heart broken multiple times Tyrion really lost his mind. But Varys thought a brain like Tyrion should not be wasted. He advised him to focus on using his brain for the welfare of the realm and soon time will heal his pain.

Varys convinces Tyrion to travel with him to Meereen. On the way, Tyrion was getting really bored. He started to ask how many days until they reach Meereen, again and again.

Varys told him it has been $N$ days since they started the journey and they have crossed one-third of the distance.

So can you find out how many days until they reach Meereen? Considering them to move at a constant speed.

Input

The input will contain a single integer $N$.

$1 \leq N \leq 10^5$

Output

Print an integer D, the number of days until they reach Meereen.

Sample

Input	Output
1	2