#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <iostream>
using namespace std;
#include <queue>
#include <math.h>

typedef struct t_cell {
    int x;
    int y;
    double distance;

    bool operator>(const t_cell &rhs) const {
        return (distance > rhs.distance);
    }
} cell;

typedef priority_queue<cell, vector<cell>, greater<cell>> workqueue;

char **G;
int H, W;
int **distances;

double heur(int x1, int y1, int x2, int y2) {
    return (
        sqrt((x1 - x2)*(x1 - x2) + (y1 - y2) * (y1 - y2))
    );
}

bool is_free(int x, int y) {
    if (x < 0 || y < 0) return false;
    if (x >= W || y >= H) return false;
    if (G[y][x] == '#') return false;

    //cout << "is_free (" << x << ", " << y << "): true" << endl;
    return true;
}

void check_n_add(workqueue &q, int x, int y) {
    if (is_free(x, y)) {
        double dist = heur(W-1, H-1, x, y);
        if (distances[y][x] > dist) {
            //cout << "Updating distance" << endl;
            distances[y][x] = dist;
        }
        else {
            return;
        }
        //cout << "Added: " << x << ", " << y << ", " << dist << endl;
        q.push({x, y, dist});
    }
}



int jump(int H, int W, char** G) {
    ::H = H;
    ::W = W;
    ::G = G;

    distances = new int*[H];
    for (int i = 0; i < H; i++) distances[i] = new int[W];

    for (int i = 0; i < H; i++)
    for (int j = 0; j < W; j++) {
        distances[i][j] = INT_MAX;
    }

    int px, py;
    px = py = 0;

    int steps = 0;
    workqueue q;
    q.push({0, 0, INT_MAX});

    while (q.size() > 0) {
        cell nearest = q.top(); q.pop();
        px = nearest.x;
        py = nearest.y;
        //cout << "moving to: " << px << ", " << py << ", " << nearest.distance << endl;

        if (px == W-1 && py == H-1) {
            //cout << "Found" << endl;
            break;
        }

        steps++;
        check_n_add(q, px+1, py);
        check_n_add(q, px+2, py);

        check_n_add(q, px, py+1);
        check_n_add(q, px, py+2);

        check_n_add(q, px-1, py);
        check_n_add(q, px-2, py);

        check_n_add(q, px, py-1);
        check_n_add(q, px, py-2);

        check_n_add(q, px+1, py+1);
        check_n_add(q, px-1, py-1);
        check_n_add(q, px-1, py+1);
        check_n_add(q, px+1, py-1);
    }

    //cout << "Steps: " << steps << endl;
    return steps;
}


int main() {
    FILE *fr, *fw;
    int H, W, i;
    char** G;

    fr = fopen("input.txt", "r");
    fw = fopen("output.txt", "w");
    assert(2 == fscanf(fr, "%d%d", &H, &W));
    G = (char**) malloc(H * sizeof(char*));
    for(i=0; i<H; i++) {
        G[i] = (char*) malloc(W * sizeof(char*));
        assert(1 == fscanf(fr, "%s", G[i]));
    }

    fprintf(fw, "%d\n", jump(H, W, G));
    fclose(fr);
    fclose(fw);
    return 0;
}