#!/usr/bin/env python3
# -*- coding: utf-8 -*-
from copy import deepcopy

# file = "./ex.txt"
file = "./input.txt"

def less_than_four(x,y,field):
    count = 0
    for posx,posy in [(x-1,y-1),(x,y-1),(x+1,y-1),(x-1,y),(x+1,y),(x-1,y+1),(x,y+1),(x+1,y+1)]:
        try:
            if posx >= 0 and posy >= 0 and field[posx][posy] == "@":
                count += 1
        except IndexError:
            pass
    if count < 4:
        return True
    else:
        return False

if __name__ == "__main__":
    solution = 0
    game_field = []
    input_file = open(file, "r")
    for line in input_file:
        line = line.strip()
        if line == "":
            continue
        tmp = []
        for b in line:
            tmp.append(b)
        game_field.append(tmp)
    input_file.close()

    while True:
        rolls_removed = 0
        game_field_copy = deepcopy(game_field)
        for i in range(len(game_field)):
            for j in range(len(game_field[0])):
                if game_field[i][j] == "@" and less_than_four(i,j,game_field):
                    solution += 1
                    rolls_removed += 1
                    game_field_copy[i][j] = "x"
        if rolls_removed > 0:
            game_field = deepcopy(game_field_copy)
        else:
            break
    print(f"Solution: {solution}")