#include<stdio.h>
char s[102][102];
int main()
{
	int n;
	scanf("%d", &n);
	int i, j;
	for (i = 0; i < n; i++)
		scanf("%s", s[i]);
	int ans = 0, f;
	for (i = 0; i < n; i++)
	{
		f = 0;
		for (j = 0; j < n; j++)
		{
			if (s[i][j] == '.')
				f++;
			else if (s[i][j] == 'B')
				f = 2;
		}
		if (f == 1)
			ans++;
	}
	for (j = 0; j < n; j++)
	{
		f = 0;
		for (i = 0; i < n; i++)
		{
			if (s[i][j] == '.')
				f++;
			else if (s[i][j] == 'B')
				f = 2;
		}
		if (f == 1)
			ans++;
	}
	f = 0;
	for (i = 0; i < n; i++)
	{
		if (s[i][i] == '.')
			f++;
		else if (s[i][i] == 'B')
			f = 2;
	}
	if (f == 1)
		ans++;
	f = 0;
	for (i = 0; i < n; i++)
	{
		if (s[i][n - i - 1] == '.')
			f++;
		else if (s[i][n - i - 1] == 'B')
			f = 2;
	}
	if (f == 1)
		ans++;
	printf("%d\n", ans);
	return 0;
}