#!/usr/bin/env python3

import numpy as np
from scipy import signal

lines = [[(1 if x == '#' else 0) for x in x.strip()] for x in open("input.txt")]
grid = np.array(lines, dtype=np.byte)
grid = np.expand_dims(grid, axis=0)
grid = np.expand_dims(grid, axis=0)
print(grid.shape)
kernel = np.ones((3, 3, 3, 3), dtype=np.byte)
kernel[1, 1, 1, 1] = 0


for iter in range(2):
    grid = np.pad(grid, pad_width=1, mode='constant', constant_values=0)
    neighbors = signal.convolve(grid, kernel, mode='same')
    set_inactive = np.logical_and(grid == 1, np.floor_divide(neighbors, 2) != 1)
    set_active = np.logical_and(grid == 0, neighbors == 3)
    grid[set_inactive] = 0
    grid[set_active] = 1
    x = np.flatnonzero(grid.sum(axis=(1, 2, 3)))
    y = np.flatnonzero(grid.sum(axis=(0, 2, 3)))
    z = np.flatnonzero(grid.sum(axis=(0, 1, 3)))
    w = np.flatnonzero(grid.sum(axis=(0, 1, 2)))
    grid = grid[x, :, :, :][:, y, :, :][:, :, z, :][:, :, :, w]

    print(iter+1, grid.shape)

print(np.sum(grid))