题目描述

By way of example, for pastures of size N=3 and N=4, here are the routes Bessie should use:

1 2 3

8 9 4

7 6 5

n=4

1  2  3  4

12 13 14 5

11 16 15 6

10  9  8 7

输入格式

A single integer: N (1 <= N <= 750)

输出格式

Lines 1..N: N space-separated integers

样例

input

3

output

1 2 3
8 9 4
7 6 5

限制与提示

时间限制：$1 \text {s}$

空间限制：$256 \text {MB}$