import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int h = sc.nextInt();
        int w = sc.nextInt();
        char[][] field = new char[h][];
        for (int i = 0; i < h; i++) {
            field[i] = sc.next().toCharArray();
        }
        ArrayDeque<Integer> deq = new ArrayDeque<>();
        boolean[][] visited = new boolean[h][w];
        deq.add(w + 1);
        while (deq.size() > 0) {
            int x = deq.poll();
            int r = x / w;
            int c = x % w;
            if (visited[r][c]) {
                continue;
            }
            visited[r][c] = true;
            boolean hasDef = false;
            for (int i = -1; i <= 1 && !hasDef; i++) {
                for (int j = -1; j <= 1 && !hasDef; j++) {
                    hasDef = (field[r + i][c + j] == '#');
                }
            }
            if (hasDef) {
                continue;
            }
            if (r > 1) {
                deq.add(x - w);
            }
            if (r < h - 2) {
                deq.add(x + w);
            }
            if (c > 1) {
                deq.add(x - 1);
            }
            if (c < w - 2) {
                deq.add(x + 1);
            }
        }
        if (!visited[h - 2][w - 2]) {
            System.out.println(0);
            return;
        }
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (i <= 2 && j <= 2) {
                    continue;
                }
                if (i >= h - 3 && j >= w - 3) {
                    continue;
                }
                if (field[i][j] == '#') {
                    continue;
                }
                field[i][j] = '#';
                deq.add(w + 1);
                for (boolean[] arr : visited) {
                    Arrays.fill(arr, false);
                }
                while (deq.size() > 0) {
                    int x = deq.poll();
                    int r = x / w;
                    int c = x % w;
                    if (visited[r][c]) {
                        continue;
                    }
                    visited[r][c] = true;
                    boolean hasDef = false;
                    for (int a = -1; a <= 1 && !hasDef; a++) {
                        for (int b = -1; b <= 1 && !hasDef; b++) {
                            hasDef = (field[r + a][c + b] == '#');
                        }
                    }
                    if (hasDef) {
                        continue;
                    }
                    if (r > 1) {
                        deq.add(x - w);
                    }
                    if (r < h - 2) {
                        deq.add(x + w);
                    }
                    if (c > 1) {
                        deq.add(x - 1);
                    }
                    if (c < w - 2) {
                        deq.add(x + 1);
                    }
                }
                if (!visited[h - 2][w - 2]) {
                    System.out.println(1);
                    return;
                }
                field[i][j] = '.';
            }
        }
        System.out.println(2);
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}