Find the factorial of a number using recursion.

Difficulty: Medium

Phase: 6 · Mixed Logical Challenges

XP Reward: 20 XP

Topics: Mixed Logical Challenges, Medium

Supported Languages: Python, JavaScript, C, C++, Java

Problem Description

Given N, print an N x N grid with zigzag (snake) row traversal numbering. Input Format: Read input from standard input (stdin). Output Format: Print the result to standard output (stdout).

Constraints

-10^9 <= N <= 10^9

Examples

Example 1

Input: 3

Output: 1 2 3 6 5 4 7 8 9

Explanation: Sample execution for input 3