import java.awt.Point;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class Exam2178 {
	static int N, M;
	static char map[][];
	static boolean visit[][];
	static Queue<Add> queue = new LinkedList<>();

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		N = sc.nextInt();
		M = sc.nextInt();

		map = new char[N][M];
		visit = new boolean[N][M];

		sc.nextLine();

		for (int i = 0; i < N; i++) {
			map[i] = sc.nextLine().toCharArray();
		}
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < M; j++) {
				visit[i][j] = false;
			}
		}

		System.out.println(travling(0, 0, 1));

		sc.close();
	}

	static int travling(int x, int y, int cnt) {

		int ret = 100000;

		visit[x][y] = true;

		if (x == N - 1 && y == M - 1) {
			return cnt;
		}
		// 오
		if ((y + 1 < M && map[x][y + 1] == '1' && !visit[x][y + 1])) {
			queue.add(new Add(new Point(x, y + 1), cnt + 1));
		}
		// 아래
		if ((x + 1 < N && map[x + 1][y] == '1' && !visit[x + 1][y])) {
			queue.add(new Add(new Point(x + 1, y), cnt + 1));
		}
		// 위
		if ((x - 1 >= 0 && map[x - 1][y] == '1' && !visit[x - 1][y])) {
			queue.add(new Add(new Point(x - 1, y), cnt + 1));
		}
		// 왼
		if ((y - 1 >= 0 && map[x][y - 1] == '1' && !visit[x][y - 1])) {
			queue.add(new Add(new Point(x, y - 1), cnt + 1));
		}

		while (!queue.isEmpty()) {
			Add p = queue.poll();
			if (!visit[p.point.x][p.point.y]) {
				int result = travling(p.point.x, p.point.y, p.cnt);
				if (result != 100000) {
					return result;
				}
			}
		}

		return ret;
	}

}

class Add {
	Point point;
	int cnt;

	public Add(Point point, int cnt) {
		super();
		this.point = point;
		this.cnt = cnt;
	}

}