#include <iostream>
using namespace std;

#define M 8
#define N 6

int Solve(int Mat[1003][1003], int m, int n, int &max_size)
{
	if (m == 0 || n == 0){
		max_size = max(max_size, Mat[m][n]);
		return Mat[m][n];
	}

	int left = Solve(Mat, m, n - 1, max_size);

	int top = Solve(Mat, m - 1, n, max_size);

	int top_left = Solve(Mat, m - 1, n - 1, max_size);


	int size = 0;
	if (Mat[m][n] == 2) {
		size = 1 + min (min(top, left), top_left);
	}

	max_size = max(max_size, size);

	return size;
}

int mat[1003][1003];

int main()
{
    int n;
    cin >> n;
    for(int i = 0; i < n; ++i)
        for(int j = 0; j < n; ++j)
            cin >> mat[i][j];


	int size = 0;

	Solve(mat, n-1, n-1, size);

	cout << size*size;

	return 0;
}