import random
import sys


grid = [ [0] * 10 for x in range(10) ]

N, S, E, W = 1, 2, 4, 8
DX         = { E: 1, W: -1, N:  0, S: 0 }
DY         = { E: 0, W:  0, N: -1, S: 1 }
OPPOSITE   = { E: W, W:  E, N:  S, S: N }


def carve_passages_from(cx, cy, grid):
    directions = [N, S, E, W]
    random.shuffle(directions)

    for direction in directions:
        nx, ny = cx + DX[direction], cy + DY[direction]

        if 0 <= ny <= len(grid) - 1 and 0 <= nx <= len(grid[ny]) - 1 and grid[ny][nx] == 0:
            grid[cy][cx] |= direction
            grid[ny][nx] |= OPPOSITE[direction]
            carve_passages_from(nx, ny, grid)

carve_passages_from(0, 0, grid)


def print_maze(grid):
    height = len(grid)
    width  = len(grid[0])

    for y in range(0, height):
        sys.stdout.write("|")
        for x in range(0, width):

            if grid[y][x] & S != 0:
                sys.stdout.write(" ")
            else:
                sys.stdout.write("_")

            if grid[y][x] & E != 0:
                if grid[y][x] | grid[y][x+1] & S != 0:
                    sys.stdout.write(" ")
                else:
                    sys.stdout.write("_")
            else:
                sys.stdout.write("|")
        print()

print_maze(grid)