#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
#include <atcoder/dsu>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;


int main(){
    int H,W; cin >> H >> W;
    vector<string> G(H+2);
    G[0] = G[H+1] = string(W+2, '#');
    rep(y,H){
        string s; cin >> s;
        G[y+1] = "#" + s + "#";
    }
    H += 2; W += 2;
    rep(y,4) rep(x,4) G[y][x] = G[H-1-y][W-1-x] = 'V';
    auto dsu = atcoder::dsu(H*W);
    rep(y0,H) rep(x0,W) rep(y1,H) rep(x1,W) if(G[y0][x0] == '#' && G[y1][x1] == '#'){
        if(abs(y0-y1) + abs(x0-x1) != 6 && abs(y0-y1) <= 3 && abs(x0-x1) <= 3){
            dsu.merge(y0*W+x0, y1*W+x1);
        }
    }
    int p0 = W-1, p1 = W*(H-1);
    if(dsu.same(p0, p1)){ cout << "0\n"; return 0; }
    rep(y,H) rep(x,W) if(G[y][x] == '.'){
        int C = 0;
        for(int dy=-3; dy<=3; dy++) for(int dx=-3; dx<=3; dx++) if(abs(dy) + abs(dx) <= 5){
            int ny = y + dy, nx = x + dx;
            if(ny >= 0 && ny < H && nx >= 0 && nx < W){
                if(dsu.same(ny*W+nx, p0)) C |= 1;
                if(dsu.same(ny*W+nx, p1)) C |= 2;
            }
        }
        if(C == 3){ cout << "1\n"; return 0; }
    }
    cout << "2\n";
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;