CF404B.Marathon

Valera takes part in the Berland Marathon. The marathon race starts at the stadium that can be represented on the plane as a square whose lower left corner is located at point with coordinates (0, 0) and the length of the side equals a meters. The sides of the square are parallel to coordinate axes.

As the length of the marathon race is very long, Valera needs to have extra drink during the race. The coach gives Valera a bottle of drink each d meters of the path. We know that Valera starts at the point with coordinates (0, 0) and runs counter-clockwise. That is, when Valera covers a meters, he reaches the point with coordinates (a, 0). We also know that the length of the marathon race equals nd + 0.5 meters.

Help Valera's coach determine where he should be located to help Valera. Specifically, determine the coordinates of Valera's positions when he covers d, 2·d, ..., n·d meters.

瓦列拉参加了贝尔兰马拉松比赛。马拉松的起点位于一个正方形体育场，该体育场在平面上可表示为一个边长为 $a$ 米的正方形，其左下角顶点坐标为 $(0,\,0)$，且正方形的各边均与坐标轴平行。

由于马拉松赛程非常长，瓦列拉在途中需要额外补充饮水。教练会在瓦列拉每跑完 $d$ 米时，向他递送一瓶饮料。已知瓦列拉从坐标为 $(0,\,0)$ 的点出发，并沿逆时针方向奔跑：即当瓦列拉跑完 $a$ 米时，他将到达坐标为 $(a,\,0)$ 的点。此外，已知整个马拉松赛程总长度为 $nd + 0.5$ 米。

请帮助瓦列拉的教练确定他应在何处等候以协助瓦列拉——具体而言，请计算出瓦列拉在恰好跑完 $d,\,2d,\,\dots,\,nd$ 米时所处的位置坐标。

The first line contains two space-separated real numbers a and d (1 ≤ a, d ≤ 105), given with precision till 4 decimal digits after the decimal point. Number a denotes the length of the square's side that describes the stadium. Number d shows that after each d meters Valera gets an extra drink.

The second line contains integer n (1 ≤ n ≤ 105) showing that Valera needs an extra drink n times.

第一行包含两个以空格分隔的实数 $a$ 和 $d$（$1 \leq a,\, d \leq 10^5$），均精确到小数点后 4 位。数值 $a$ 表示描述该体育场的正方形边长；数值 $d$ 表示瓦莱拉每跑 $d$ 米即可获得一次额外饮品。

第二行包含一个整数 $n$（$1 \leq n \leq 10^5$），表示瓦莱拉总共需要获得 $n$ 次额外饮品。

Print n lines, each line should contain two real numbers x__i and y__i, separated by a space. Numbers x__i and y__i in the i-th line mean that Valera is at point with coordinates (x__i, y__i) after he covers i·d meters. Your solution will be considered correct if the absolute or relative error doesn't exceed 10 - 4.

Note, that this problem have huge amount of output data. Please, do not use cout stream for output in this problem.

输出 n 行，每行包含两个实数 x__i 和 y__i，用空格分隔。第 i 行中的数 x__i 和 y__i 表示 Valera 在行进 i·d 米后所处位置的坐标 (x__i, y__i)。若你的解的绝对误差或相对误差均不超过 10 - 4，则视为正确。

注意：本题输出数据量极大，请勿在本题中使用 cout 流进行输出。