def place_half_cover(n, arena):
    for i in range(n):
        x = np.random.randint(0, (arena.size - 1))
        y = np.random.randint(0, (arena.size - 1))
        if (arena.arena[(x, y)] == 0):
            arena.arena[(x, y)] = 3
    return arena
def place_half_cover(n, arena):
    for i in range(n):
        x = np.random.randint(0, (arena.size - 1))
        y = np.random.randint(0, (arena.size - 1))
        if (arena.arena[(x, y)] == 0):
            arena.arena[(x, y)] = 3
    return arena