import java.util.HashSet;

import java.util.Scanner;

import java.util.Set;

public class Main {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

String[] ss = input.nextLine().trim().split(" +");

int n = Integer.parseInt(ss[0]); //数组的第一部分为迷宫的长

int m = Integer.parseInt(ss[1]); //数组的第二部分为迷宫的宽

char[][] data = new char[n][];

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

data[i] = input.nextLine().trim().toCharArray(); //正文部分为迷宫的内部构造

}

Set<String> set = new HashSet<>(); //set用来保存走的路径

set.add("0,0"); //将迷宫的左上角(0, 0)设为起点, 右下角设为终点

System.out.println(fun(data, set, n-1 + "," +(m -1)));

}

public static int fun(char[][] data, Set<String> from, String goal) {

if (from.contains(goal)) return 0; //起点与终点重合,需要0步完成

Set<String> set = new HashSet<>(); //from相邻的未访问的点

for (Object obj : from) {

String[] ss = ((String) obj).split(",");

int y = Integer.parseInt(ss[0]);

int x = Integer.parseInt(ss[1]);

if (y > 0 && data[y - 1][x] == '.') {

data[y - 1][x] = '*';

set.add(y - 1 + "," + x);

}

if (y < data.length - 1 && data[y + 1][x] == '.') {

data[y + 1][x] = '*';

set.add(y + 1 + "," + x);

}

if (y > 0 && data[y][x - 1] == '.') {

data[y][x - 1] = '*';

set.add(y + "," + (x - 1));

}

if (y < data.length - 1 && data[y][x + 1] == '.') {

data[y][x + 1] = '*';

set.add(y + "," + (x + 1));

}

}

if (set.isEmpty()) return -1;

int r = fun(data, set, goal); //分层遍历 广度优先遍历

if (r < 0) return -1; //找不到出口 返回-1

return r + 1;

}

}