#include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;
int dr[] = {-1, 1, 0, 0}; // 0: Up, 1: Down, 2: Left, 3: Right
int dc[] = {0, 0, -1, 1};

struct State {
    int r, c, d;
};

int dist_turn[1005][1005][4];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int r, c;
    if (!(cin >> r >> c)) return 0;
    vector<string> grid(r);
    for (int i = 0; i < r; i++) {
        cin >> grid[i];
    }
    for (int i = 0; i < r; i++) {
        for (int j = 0; j < c; j++) {
            for (int k = 0; k < 4; k++) {
                dist_turn[i][j][k] = INF;
            }
        }
    }
    deque<State> dq;
    for (int d = 0; d < 4; d++) {
        dist_turn[0][0][d] = 0;
        dq.push_back({0, 0, d});
    }
    while (!dq.empty()) {
        State curr = dq.front();
        dq.pop_front();

        // 1. Move straight in current direction
        int nr = curr.r + dr[curr.d];
        int nc = curr.c + dc[curr.d];
        if (nr >= 0 && nr < r && nc >= 0 && nc < c && grid[nr][nc] == '.') {
            if (dist_turn[curr.r][curr.c][curr.d] < dist_turn[nr][nc][curr.d]) {
                dist_turn[nr][nc][curr.d] = dist_turn[curr.r][curr.c][curr.d];
                dq.push_front({nr, nc, curr.d});
            }
        }

        // 2. Change direction on-the-spot
        for (int nd = 0; nd < 4; nd++) {
            if (nd != curr.d) {
                if (dist_turn[curr.r][curr.c][curr.d] + 1 < dist_turn[curr.r][curr.c][nd]) {
                    dist_turn[curr.r][curr.c][nd] = dist_turn[curr.r][curr.c][curr.d] + 1;
                    dq.push_back({curr.r, curr.c, nd});
                }
            }
        }
    }
    int ans = INF;
    for (int d = 0; d < 4; d++) {
        ans = min(ans, dist_turn[r-1][c-1][d]);
    }
    cout << (ans == INF ? -1 : ans) << "\n";
    return 0;
}