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

public class Main { 

    static class node{
        int x,y;
        node(int x,int y){
            this.x=x;
            this.y=y;
        }
    }

    static int r,c;
    static char[][] arr;
    static int[][] dis;
    static int[] dx = {-1,1,0,0};
    static int[] dy = {0,0,-1,1};

    public static int bfs(int x,int y) {
        Queue<node> que = new LinkedList<node>();
        que.offer(new node(x,y));//将起点入队
        dis[x][y]=0;
        while(!que.isEmpty()) {
            node t = que.poll();//移除并返回队列头部的元素
            if(t.x==r-1&&t.y==c-1) {//找到出口
                return dis[t.x][t.y];
            }
            for(int a=0;a<4;a++) {
                int newx = t.x+dx[a];
                int newy = t.y+dy[a];
                if(newx>=0&&newx<r&&newy>=0&&newy<c&&arr[newx][newy]=='.'&&dis[newx][newy]==0) {
                    dis[newx][newy] = dis[t.x][t.y]+1;//dis是表示的是当前元素的层数，下一层的层数是当前的层数加1；
                    que.offer(new node(newx,newy));//将当前元素入队；
                    //BFS不用回溯
                }
            }
        }
        return -1;
    }

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        r=input.nextInt();
        c=input.nextInt();
        arr = new char[r][c];
        dis = new int[r][c];
        for(int i=0;i<r;i++) {
            arr[i] = input.next().toCharArray();
        }
        System.out.println(bfs(0,0)+1);
    }

}