Problem Statement

#nck { width: 30px; height: auto; }

Construct an $N$-gon that satisfies the following conditions:

• The polygon is simple (see notes for the definition).
• Each edge of the polygon is parallel to one of the coordinate axes.
• Each coordinate is an integer between $0$ and $10^9$, inclusive.
• The vertices are numbered $1$ through $N$ in counter-clockwise order.
• The internal angle at the $i$-th vertex is exactly $a_i$ degrees.

In case there are multiple possible answers, you can output any.

Notes

A polygon is called simple if each edge has a positive length, and no two edges have a common point (except for adjacent edges touching at a vertex).

Constraints

• $3 ≤ N ≤ 1000$
• $a_i$ is either $90$ or $270$.

Input

The input is given from Standard Input in the following format:

$N$ $a_1$ : $a_N$

Output

In case the answer exists, print the answer in the following format:

$x_1$ $y_1$ : $x_N$ $y_N$

Here $(x_i, y_i)$ are the coordinates of the $i$-th vertex.

In case the answer doesn't exist, print a single -1.

Sample Input 1

8
90
90
270
90
90
90
270
90

Sample Output 1

0 0
2 0
2 1
3 1
3 2
1 2
1 1
0 1

Sample Input 2

3
90
90
90

Sample Output 2

-1