queue<pair<int, int>> q;
for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
        if (maze[i][j] == 'A') {
            start = {i, j};
            distA[i][j] = 0;
        } else if (maze[i][j] == 'M') {
            monsters.push_back({i, j});
            distM[i][j] = 0;
            q.push({i, j});
        }
    }
}

bfs(q, distM);  // BFS for monsters

q.push(start);
bfs(q, distA);  // BFS for player

vector<vector<int>> exitDist = distA;
for (auto [x, y] : monsters) {
    if (distA[x][y] != -1 && distA[x][y] <= distM[x][y]) {
        cout << "NO" << endl;
        return 0;
    }
}

int ex = -1, ey = -1;
for (int i = 0; i < n; i++) {
    if (maze[i][0] == '.' || maze[i][0] == 'A') {
        if (distA[i][0] != -1 && (distA[i][0] < distM[i][0] || distM[i][0] == -1)) {
            ex = i, ey = 0;
            break;
        }
    }
    if (maze[i][m-1] == '.' || maze[i][m-1] == 'A') {
        if (distA[i][m-1] != -1 && (distA[i][m-1] < distM[i][m-1] || distM[i][m-1] == -1)) {
            ex = i, ey = m-1;
            break;
        }
    }
}
for (int j = 0; j < m; j++) {
    if (maze[0][j] == '.' || maze[0][j] == 'A') {
        if (distA[0][j] != -1 && (distA[0][j] < distM[0][j] || distM[0][j] == -1)) {
            ex = 0, ey = j;
            break;
        }
    }
    if (maze[n-1][j] == '.' || maze[n-1][j] == 'A') {
        if (distA[n-1][j] != -1 && (distA[n-1][j] < distM[n-1][j] || distM[n-1][j] == -1)) {
            ex = n-1, ey = j;
            break;
        }
    }
}

if (ex == -1) {
    cout << "NO" << endl;
    return 0;
}

cout << "YES" << endl;
vector<char> path;
while (ex != start.first || ey != start.second) {
    for (int i = 0; i < 4; i++) {
        int nx = ex - dx[i], ny = ey - dy[i];
        if (isValid(nx, ny) && distA[nx][ny] == distA[ex][ey] - 1) {
            path.push_back(dir[i]);
            ex = nx;
            ey = ny;
            break;
        }
    }
}
reverse(path.begin(), path.end());
cout << path.size() << endl;
for (char c : path) cout << c;
cout << endl;

return 0;

cout << S;

return 0;