<p>You are given an integer <code>n</code>. You have an <code>n x n</code> binary grid <code>grid</code> with all values initially <code>1</code>'s except for some indices given in the array <code>mines</code>. The <code>i<sup>th</sup></code> element of the array <code>mines</code> is defined as <code>mines[i] = [x<sub>i</sub>, y<sub>i</sub>]</code> where <code>grid[x<sub>i</sub>][y<sub>i</sub>] == 0</code>.</p>
<p>Return <em>the order of the largest <strong>axis-aligned</strong> plus sign of </em>1<em>'s contained in </em><code>grid</code>. If there is none, return <code>0</code>.</p>
<p>An <strong>axis-aligned plus sign</strong> of <code>1</code>'s of order <code>k</code> has some center <code>grid[r][c] == 1</code> along with four arms of length <code>k - 1</code> going up, down, left, and right, and made of <code>1</code>'s. Note that there could be <code>0</code>'s or <code>1</code>'s beyond the arms of the plus sign, only the relevant area of the plus sign is checked for <code>1</code>'s.</p>
