import sys
from collections import deque
import heapq
import time
import os

class Cell:
    """клетка лабиринта"""
    def __init__(self, x, y, is_wall=False, is_start=False, is_exit=False):
        self.x = x
        self.y = y
        self.is_wall = is_wall
        self.is_start = is_start
        self.is_exit = is_exit
    
    def is_passable(self):
        return not self.is_wall
    
    def __repr__(self):
        return f"Cell({self.x}, {self.y})"


class Maze:
    """лабиринт"""
    def __init__(self, width, height):
        self.width = width
        self.height = height
        self.cells = [[Cell(x, y) for x in range(width)] for y in range(height)]
        self.start = None
        self.exit = None
    
    def get_cell(self, x, y):
        if 0 <= x < self.width and 0 <= y < self.height:
            return self.cells[y][x]
        return None
    
    def get_neighbors(self, cell):
        neighbors = []
        directions = [(-1, 0), (1, 0), (0, -1), (0, 1)]
        for dx, dy in directions:
            neighbor = self.get_cell(cell.x + dx, cell.y + dy)
            if neighbor and neighbor.is_passable():
                neighbors.append(neighbor)
        return neighbors
    
    def set_start(self, x, y):
        cell = self.get_cell(x, y)
        if cell:
            cell.is_start = True
            self.start = cell
    
    def set_exit(self, x, y):
        cell = self.get_cell(x, y)
        if cell:
            cell.is_exit = True
            self.exit = cell