#CCBCHBA0000106. Lưới chẵn lẻ theo vị trí (Position-Parity Grid)

Lưới chẵn lẻ theo vị trí (Position-Parity Grid)

Position-Parity Grid

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given an rr-by-cc grid with 1-based indices, print 1 at (i,j)(i,j) when i+ji+j is even; otherwise print 0. Output rr rows of exactly cc adjacent characters with no spaces.

Input

One line contains rr and cc in this order.

Output

Print the grid as described.

Subtasks

  • Subtask 1 (20%): 1≤r,c≤51\le r,c\le 5.

  • Subtask 2 (30%): 1≤r,c≤151\le r,c\le 15.

  • Subtask 3 (50%): 1≤r,c≤301\le r,c\le 30.

Examples

Example 1

Input:

2 3

Output:

101
010

Explanation:

There are 2 rows and 3 columns. Cell (1,1) is 1, and parity alternates along rows and columns.

Example 2

Input:

1 1

Output:

1

Explanation:

There are 1 rows and 1 columns. Cell (1,1) is 1, and parity alternates along rows and columns.