import java.util.List;

/**
 * @author /u/Philboyd_Studge on 12/17/2015.
 */
public class Advent18 {

    static boolean[][] grid = new boolean[100][100];

    static boolean part2 = false;


    public static int countNeighbors(int x, int y) {
        int count = 0;
        for (int i = x > 0 ? -1 : 0; i < (x < 99 ? 2 : 1); i++) {
            for (int j = y > 0 ? -1 : 0; j < (y < 99 ? 2 : 1); j++) {
                if (!(i == 0 && j == 0) && grid[x + i][y + j]) count++;
            }
        }
        return count;
    }

    public static int countLightsOn() {
        int count = 0;
        for (boolean[] each : grid) {
            for (boolean every : each) {
                if (every) count++;
            }

        }
        return count;
    }

    public static void tick() {
        boolean[][] newGrid = new boolean[100][100];
        for (int i = 0; i < 100; i++) {
            for (int j = 0; j < 100; j++) {
                int neighbors = countNeighbors(i, j);
                if (grid[i][j] && (neighbors < 2 || neighbors > 3)) {
                    newGrid[i][j] = false;
                } else {
                    if (neighbors == 3) {
                        newGrid[i][j] = true;
                    } else {
                        newGrid[i][j] = grid[i][j];
                    }
                }
            }
        }
        if (part2) {
            newGrid[0][0] = true;
            newGrid[0][99] = true;
            newGrid[99][99] = true;
            newGrid[99][0] = true;
        }
        grid = newGrid;
    }
    public static void main(String[] args) {
        //boolean[][] grid = new boolean[100][100];

        List<String> input = FileIO.getFileAsList("advent18.txt");

        for (int i = 0; i < 100; i++) {
            String line = input.get(i);
            for (int j = 0; j < 100; j++) {
                grid[i][j] = line.charAt(j)=='#';
            }
        }

        // hack
        if (part2) grid[99][0] = true;

        for (int i = 0; i < 100; i++) tick();
        System.out.println(countLightsOn());
    }
}