Description

Input a positive integer n and generate a pyramid with n levels. See the sample for the detailed pattern. Note that when n=1, there is no floor.

Input Format

The first line contains an integer n (1≤n≤100), representing the number of levels.

Output Format

Output an n-level pyramid. Note that the pyramid is completely symmetrical, and the same number of spaces should be output on the right side as on the left side.

Sample

10

         /\
        /__\
       /____\
      /______\
     /________\
    /__________\
   /____________\
  /______________\
 /________________\
/__________________\