Problem D
Raðir

Three of Hearts by Harry Shelton, Unsplash

You just lost a game to your friend. This does not bother you too much, since you just learned how to play the game, but you want to learn from your mistakes. Looking over your cards, you wonder how early you could have achieved a sequence, had you played optimally.

Input

The first line of the input contains two integers $n$, the total number of cards, and $p$, the number of cards you can keep in your hand, where $3\le p\le n\le {10}^6$. Then there are $n$ lines, the $j$-th of which contains two integers $c_j$ and $k_j$, the suit and value of the $j$-th card you receive, where $1\le c_j\le 4$ and $1\le k_j\le 13$. The first $p$ cards are the cards you got dealt initially, and the subsequent $n-p$ cards are the cards you drew, in that order.

Output

The output should contain one integer, the fewest number of turns it could have taken you to obtain a sequence. If no sequence can be optained, output “Neibb”.

Scoring

5 3
1 1
1 2
4 3
2 3
1 3

2

5 3
1 1
1 2
1 4
1 3
1 5

1

5 3
1 1
1 2
1 4
1 5
1 7

Neibb