#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#define MAXH 2005
#define MAXW 2005

static char g[MAXH][MAXW];

int main(void) {
    int H, W;
    scanf("%d %d", &H, &W);

    for (int i = 0; i < H; i++) {
        scanf("%s", g[i]);
    }

    int R = 2 * H - 1;
    int C = 2 * W - 1;
    int N = R * C;

    unsigned char *vis = (unsigned char *)calloc(N, 1);
    int *q = (int *)malloc(sizeof(int) * N);
    if (!vis || !q) return 0;

    int sr = 0, sc = 0;
    int gr = R - 1, gc = C - 1;
    int s = sr * C + sc;
    int t = gr * C + gc;

    int head = 0, tail = 0;
    q[tail++] = s;
    vis[s] = 1;

    int dist = 0;
    const int dr[4] = {-1, 1, 0, 0};
    const int dc[4] = {0, 0, -1, 1};

    while (head < tail) {
        int qs = tail - head;
        while (qs--) {
            int v = q[head++];
            if (v == t) {
                printf("%d\n", dist);
                free(vis);
                free(q);
                return 0;
            }

            int r = v / C;
            int c = v % C;

            for (int dir = 0; dir < 4; dir++) {
                int nr = r + dr[dir];
                int nc = c + dc[dir];

                if (nr < 0 || nr >= R || nc < 0 || nc >= C) continue;

                if ((nr % 2 == 0) && (nc % 2 == 0)) {
                    if (g[nr / 2][nc / 2] == '#') continue;
                }

                int ni = nr * C + nc;
                if (vis[ni]) continue;

                vis[ni] = 1;
                q[tail++] = ni;
            }
        }
        dist++;
    }

    printf("-1\n");
    free(vis);
    free(q);
    return 0;
}