#include <iostream>
#include <fstream>
#include <vector>

void findStartCoordinates(int start_x, int start_y,
                          std::vector<std::vector<char>> maze) {
    for (int i = 0; i < maze.size(); i++) {
        for (int j = 0; j < maze[0].size(); j++) {
            if (maze[i][j] == 'A') {
                start_x = i;
                start_y = j;
                return;
            }
        }
    }
}

bool solveMaze(int x, int y, std::vector<std::vector<char>>& maze) {
    if (maze[x][y] == 'B') return true;
    if (x < 0 || x >= maze.size() ||
        y < 0 || y >= maze.size() ||
        maze[x][y] != ' ') return false;

    maze[x][y] = '.';

    if (solveMaze(x, y - 1, maze)) return true;
    if (solveMaze(x + 1, y, maze)) return true;
    if (solveMaze(x, y + 1, maze)) return true;
    if (solveMaze(x - 1, y, maze)) return true;

    maze[x][y] = ' ';
    return false;
}

void printMaze(std::vector<std::vector<char>> maze) {
    for (auto line : maze) {
        for (auto obs : line) {
            std::cout << obs;
        }
        std::cout << '\n';
    }
}

int main() {
    std::ifstream file("labirynt.txt");
    std::vector<std::vector<char>> maze;
    for (std::string line;
         std::getline(file, line);
         maze.emplace_back(line.begin(), line.end()));

    int start_x, start_y;
    findStartCoordinates(start_x, start_y, maze);

    maze[start_x][start_y] = ' ';
    solveMaze(start_x, start_y, maze);
    maze[start_x][start_y] = 'A';

    printMaze(maze);
}