P10042 [AtCoder] AtCoder Grand Contest 025 - Choosing Points
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题目描述

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.

Constraints

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

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.

Examples

Input

2 1 2

Output

0 0
0 2
2 0
2 2

Input

3 1 5

Output

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

输入格式

见题面

输出格式

见题面

样例输入
3 1 5
样例输出
0 0 0 2 0 4 1 1 1 3 1 5 2 0 2 2 2 4