You have gotten yourself a gerbil and a nice large cage for it. You have even bought a lot of different toys for it to play with: a ball, a set of dominoes, and even a real Klein bottle! And still, to your great dismay, your gerbil seems to be upset with its new home! You ponder for a long time how you could make your gerbil happy. What could you still get your gerbil‽ And then it strikes you: The gerbil needs a wheel to run in! And no ordinary gerbil wheel suffices; you decide to order one with a custom paint job!

You know that the radius of the wheel needs to be exactly r units of length, and that the coloring must satisfy strict requirements. For simplicity, you model the wheel as a circle where each circular arc has a specific color. The coloring of the circle needs to satisfy the following requirements:

• The wheel needs to be fully painted with blue and orange colors. The blue color calms the gerbil down while the orange color encourages the gerbil to move faster!
• When the gerbil is standing on an orange point of the wheel, there must be a blue point at distance exactly 1 in either direction. Otherwise the gerbil might get too stressed.
• When the gerbil is standing on a blue point of the wheel, there must be an orange point at distance exactly 1 in both directions. Otherwise the gerbil might get bored.

To refer to the points of the wheel, you use the following convention: You mark one of the points of the wheel as the origin. You then refer to each point by their distance from the origin along the wheel in counter-clockwise orientation. Hence every point is assigned a real number between [0, 2\pi r].

All distances, apart from the radius, are measured along the arc of the wheel.

Input

Input consists of one integer r, the radius of the gerbil wheel.

Output

Output a list of arc segments of the wheel that need to be colored blue. The rest of the wheel is colored orange.

Each line of the output consists of two rational numbers, x and y, describing a half-open interval [x, y) of points on the wheel that are colored blue. They must satisfy 0 \le x < y \le 2\pi r. Each rational number \frac{p}{q} must be written in form p/q, where 1 \le q \le 10^6.

The output may consist of at most 10^5 segments.

Constraints

• 1 \le r \le 1000

Example

Input:

1

Output:

0/1 2/2
21/10 31/10
46/11 57/11

The example is illustrated below.