Largest Connected Region in a Binary Matrix

You are given an \( n \times n \) binary matrix, where each element is either 0 or 1. A region is defined as a group of adjacent 1's, where adjacent means cells sharing a side (up, down, left, or right). Your task is to determine the size of the largest connected region of 1's in the matrix.

Note: Diagonally adjacent cells are not considered connected.

Example:

Input:
4
1 1 0 0
1 0 1 0
0 0 1 1
1 0 0 0
Output:
3

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In the above example, the largest connected region has size 3.

inputFormat

The first line of input contains an integer \( n \) denoting the size of the matrix. The following \( n \) lines each contain \( n \) space-separated integers (either 0 or 1) representing the rows of the matrix.

outputFormat

Output a single integer indicating the size of the largest connected region of 1's.

## sample

4
1 1 0 0
1 0 1 0
0 0 1 1
1 0 0 0

3

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