Description

A snake-like triangle with $n$ rows is formed by arranging natural numbers starting from $1$ in an upper triangular matrix.
The first row has $n$ numbers, and each subsequent row has one fewer number. See the sample for the specific pattern.

Input Format

Input an integer $n$, where $1 \le n \le 100$.

Output Format

Output the snake-like triangle with $n$ rows.

Sample

5

1 3 6 10 15
2 5 9 14
4 8 13
7 12
11