Snowflake is a classical fractal curve. It is generated starting from equilateral triangle (等边三角形) and iteratively replacing the mid one-third of an edge with the other two edges of a new equilateral triangle pointing outwards.
After infinite iterations, the snowflake becomes a $1.26$ dimension geometry. These can be seen by scaling an edge of the snowflake by $3\times$:
3x __/\__
======> \ /
__/\__ __/\__/ \__/\__
One edge becomes 4 edges. Hence the “volume” of the snowflake scales by $4$ when its side scales by $3$. This relation yields $\frac{\ln 4}{\ln 3}\approx1.26$. In comparison, the “volume” of 2D geometries, i.e. the area, scales by $9$. Check circles and squares by yourself!
Your task is to print an ASCII art of the snowflake.
Input: The input is a single integer $0\le n\le7$, indicating the number of iterations.
Output: No spaces after lines are allowed.
Example Input 1
0
Example Output 1
__
\/
Example Input
1
Example Output
__/\__
\ /
/_ _\
\/