rt，代码判太多-1

n#include <bits/stdc++.h>
using namespace std;
char a[45][45];



int dirx[] = {0, 0, 1, -1}, diry[] = {1, -1, 0, 0}, n, m, cnt, sx, sy, ex, ey, ans = INT_MAX;
bool vis[45][45], fl;

struct point {
	int x, y, step, way;
};

void bfs() {
	queue<point>q;
	for (int i = 0; i < 4; i++)
		if (a[sx + dirx[i]][sy + diry[i]] == '.')
			q.push({sx + dirx[i], sy + diry[i], 0, i});
	while (!q.empty()) {
		point now = q.front();
		q.pop();
		int x = now.x, y = now.y, step = now.step, way = now.way;
		//cout << x << " " << y << " " << step << " " << way << '\n';
		if (x == ex && y == ey) {
			ans = min(ans, step);
			fl = 1;
			continue;
		}
		vis[x][y] = true;
		for (int i = 0; i < 4; i++) {
			if (x + dirx[i] < 1 || x + dirx[i] > n)
				continue;
			if (y + diry[i] < 1 || y + diry[i] > m)
				continue;
			if (vis[x + dirx[i]][y + diry[i]])
				continue;
			if (a[x + dirx[i]][y + diry[i]] == 'x')
				continue;
			q.push({x + dirx[i], y + diry[i], step + (int)(i != way), i});
		}
	}
}

int main() {
	cin >> n;
	m = n;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			cin >> a[i][j];
			if (a[i][j] == 'A')
				sx = i, sy = j;
			if (a[i][j] == 'B')
				ex = i, ey = j;
		}
	}
	//cout<<sx<<" "<<
	bfs();
	if (!fl)
		cout << -1;
	else
		cout << ans;
	return 0;
}