Problem Statement

Takahashi is doing a research on sets of points in a plane.
Takahashi thinks a set S of points in a coordinate plane is a good set when S satisfies both of the following conditions:

• The distance between any two points in S is not $\sqrt{D_1}$.
• The distance between any two points in S is not $\sqrt{D_2}$.

Here, D_1 and D_2 are positive integer constants that Takahashi specified.
Let X be a set of points (i,j) on a coordinate plane where i and j are integers and satisfy 0 ≤ i,j < 2N.
Takahashi has proved that, for any choice of D_1 and D_2, there exists a way to choose N^2 points from X so that the chosen points form a good set.
However, he does not know the specific way to choose such points to form a good set.
Find a subset of X whose size is N^2 that forms a good set.

Input

Input is given from Standard Input in the following format:
N D_1 D_2

Output

Print N^2 distinct points that satisfy the condition in the following format:
x_1 y_1
x_2 y_2
:
x_{N^2} y_{N^2}

Here, (x_i,y_i) represents the i-th chosen point.
0 ≤ x_i,y_i < 2N must hold, and they must be integers.
The chosen points may be printed in any order.
In case there are multiple possible solutions, you can output any.

Constraints

• 1 ≤ N ≤ 300
• 1 ≤ D_1 ≤ 2×10^5
• 1 ≤ D_2 ≤ 2×10^5
• All values in the input are integers.

Sample Input 1

2 1 2

Sample Output 1

0 0
0 2
2 0
2 2

Among these points, the distance between 2 points is either 2 or $2\sqrt{2},$ thus it satisfies the condition.

Sample Input 2

3 1 5

Sample Output 2

0 0
0 2
0 4
1 1
1 3
1 5
2 0
2 2
2 4

见题面 Input 部分

见题面 Output 部分