#!/usr/bin/env python3

import numpy as np
from scipy.signal import convolve2d

arr = np.array([[int(n) for n in line.strip()] for line in open("input.txt")])
flashes = 0

for step in range(100):
    arr = arr + 1
    next_arr = arr
    mask = np.zeros_like(arr)
    changes = 0
    while True:
        mask[next_arr >= 10] = 1
        next_arr = arr + convolve2d(mask, np.array([[1, 1, 1], [1, 0, 1], [1, 1, 1]]), boundary='fill', mode='same')
        if changes == (changes := np.sum(mask)):
            arr = next_arr
            arr[arr >= 10] = 0
            flashes += np.sum(mask)
            break

print(flashes)