Untitled

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    
    static int[][] D = new int[101][101];
    static int[][] board = new int[101][101];
    static boolean [][] chk = new boolean[101][101];
    static int N;
    static int M;
    static int[] dy = {0,0,1,-1};
    static int[] dx = {1,-1,0,0};
    static int INF = 130103330;
    public static void main(String[] args) 
    throws IOException{
        INPUT();
        SOLVE();
        // print();
    }

    static void INPUT() throws IOException{
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(bf.readLine());
        N = Integer.parseInt(st.nextToken());
        M = Integer.parseInt(st.nextToken());
        for(int i = 0;i<N;i++){
            String nxt = bf.readLine();
            int j =0;
            for(char c : nxt.toCharArray()){
                board[i][j] = (c=='1') ? 1 : 0;
                D[i][j++] = INF;
            }
        }
    }
    
    static void print(){
        for (int i = 0; i < N; i++) {
            for(int j = 0;j<M;j++){
                // System.out.print(board[i][j] + " ");
                System.out.print(D[i][j] + " ");
            }
            System.out.println();
        }
    }

    static void SOLVE(){
        D[0][0] = 1;
        DFS(0,0);
        System.out.println(D[N-1][M-1]);
    }

    static void DFS(int y, int x){
        if(isOutside(y, x) || board[y][x]==0){
            return;
        }
        for(int i = 0;i<4;i++){
            int ny = y + dy[i];
            int nx = x + dx[i];
            if(isOutside(ny, nx)) continue;
            if(board[ny][nx] == 1 && D[ny][nx]>D[y][x]+1){
                // System.out.println(ny +" " + nx);
                D[ny][nx] = D[y][x] + 1;
                DFS(ny, nx);
            }
        }
    }

    static boolean isOutside(int ny, int nx){
        return (0>ny || ny>=N || 0>nx || nx>=M);
    }
}