static int[][] visited;

static int N;

static int M;

static int[] dc = {0, 0, 1, -1};

static int[] dr = {-1, 1, 0, 0};

static int minValue = (int) 1e9;

public static void main(String[] args) throws IOException {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

StringTokenizer st = new StringTokenizer(br.readLine());

N = Integer.parseInt(st.nextToken());

M = Integer.parseInt(st.nextToken());

int[][] miro = new int[N][M];

for (int i = 0; i < N; i++) {

String s = br.readLine();

for (int j = 0; j < M; j++) {

miro[i][j] = Integer.parseInt(String.valueOf(s.charAt(j)));

}

}

visited = new int[N][M];

visited[0][0] = 1;

BFS(0,0,miro);

System.out.println(visited[N-1][M-1]);

}

private static void BFS(int col, int row, int[][] miro) {

Deque<int[]> dq = new LinkedList<>();

dq.offer(new int[]{col, row});

while (!dq.isEmpty()) {

int[] now = dq.pollFirst();

int nc = now[0];

int nr = now[1];

for (int i = 0; i < 4; i++) {

int cc = dc[i] + nc;

int cr = dr[i] + nr;

if (0 <= cc && cc < N && 0 <= cr && cr < M && visited[cc][cr] == 0) {

if (miro[cc][cr] == 1) {

dq.offer(new int[]{cc, cr});

visited[cc][cr] = visited[nc][nr] + 1;

}

}

}

}

}

private static void DFS(int col, int row, int count, int[][] miro) {

if (col == N - 1 && row == M - 1) {

minValue = Math.min(minValue, count);

return;

}

for (int i = 0; i < 4; i++) {

int cc = dc[i] + col;

int cr = dr[i] + row;

if (0 <= cc && cc < N && 0 <= cr && cr < M && visited[cc][cr] == 0) {

if (miro[cc][cr] == 1) {

visited[cc][cr] = 1;

DFS(cc, cr, count+1, miro);

visited[cc][cr] = 0;

}

}

}

}

}