#include <stdio.h>
#define SIZE 201
#define INFARM(a, b, c, d) a > 0 && b > 0 && c > 0 && d > 0 && a <= length && b <= length && c <= length && d <= length
#define AREA(a, b) a * a + b * b
int i, j, x, y, length, p, q, max_area;
char farm[SIZE][SIZE];
int main(void)
{
max_area = 0;
scanf("%d", &length);
for(i = 1; i <= length; ++i)
{
getchar();
for(j = 1; j <= length; ++j)
farm[i][j] = getchar();
}
for(i = 1; i <= length; ++i)
for(j = 1; j <= length; ++j)
if(farm[i][j] != 'B')
for(x = length; x >= 1; --x)
for(y = length; y >= j; --y)
{
p = i - x;
q = j - y;
if(AREA(p, q) < max_area)
continue;
if(farm[x][y] == 'B' || (farm[i][j] == farm[x][y] && farm[i][j] == '*'))
continue;
if((INFARM(i + q, j - p, x + q, y - p) && farm[i + q][j - p] == 'J'
&& farm[x + q][y - p] == 'J') || (INFARM(i - q, j + p, x - q, y + p)
&& farm[i - q][j + p] == 'J' && farm[x - q][y + p] == 'J'))
{
max_area = AREA(p, q);
}
}
printf("%d\n", max_area);
return 0;
}