## Problem Statement

It is the year 1945. You are a Soviet Super-Soldier and can predict the future. You have just
completed a mission to sabotage the dying capital of the Third Reich. You need to safely return to
your *comrades* advancing on the outskirts of Berlin.

However, there are several **Katyusha** units that are currently firing on the area between you and
your comrades. There are three types of **Katyushas**: the light *BM-8*, with an impact radius of 8
meters, the intermediate *BM-13*, with an impact radius of 13 meters, and the massive *BM-30*, with
an impact radius of a whopping 30 meters. Comrade Super-Soldier, you need to determine whether
you can return to your comrades and complete the final assault in the Great Patriotic War!

There will be a grid of 101 by 101 squares. Each of the $N$ **Katyusha** units will turn a square at
($x, y$) into a death-zone (**DZ**). You start from the bottom left corner (square ($0, 0$)) of the grid and
must reach the top right corner (square ($100, 100$)) of the grid without entering any $DZ$. You may
travel in any direction laterally, but may not travel diagonally. Good luck, *comrade*!

## Input Specification

The first line will contain one integer, $0 \le N \le 5000$. Each of the next $N$ lines will contain 2 space-separated integers, $0 \le x_i \le 100$ and $0 \le y_i \le 100$.

## Output Specification

You will print a single character, $y$ to indicate that you can reach your comrades or $n$ to indicate that you will die for the motherland.

## Sample Input 1

```
2
0 1
1 0
```

## Sample Output 1

```
n
```

## Sample Input 2

```
21
0 1
1 1
2 1
4 0
4 1
4 2
4 3
3 3
2 3
1 3
0 7
1 7
2 7
3 7
4 7
5 7
6 7
6 6
6 5
6 4
6 3
```

## Sample Output 2

```
y
```