#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

char c[53][53];

int n, m, dis[18][18], belong[53][53], f[40000][18], cnt = 0, qx[2500000], qy[2500000];

int far[2500000], head, tail;

bool vis[53][53];

inline void _(int x, int y) {

	belong[x][y] = cnt;

	vis[x][y] = 1;

	if (x > 1 && c[x - 1][y] == 'X' && !vis[x - 1][y])

		_(x - 1, y);

	if (y > 1 && c[x][y - 1] == 'X' && !vis[x][y - 1])

		_(x, y - 1);

	if (x < n && c[x + 1][y] == 'X' && !vis[x + 1][y])

		_(x + 1, y);

	if (y < m && c[x][y + 1] == 'X' && !vis[x][y + 1])

		_(x, y + 1);

}

inline void __(int x) {

	int nowx, nowy;

	while (head != tail) {

		++head; if ( head >= 2500000) head %= 2500000;

		nowx = qx[head];

		nowy = qy[head];

		if (nowx > 1 && !vis[nowx - 1][nowy] && c[nowx - 1][nowy] != '.') {

			if (c[nowx - 1][nowy] == 'S') {

				++tail; if (tail >= 2500000) tail %= 2500000;

				qx[tail] = nowx - 1;

				qy[tail] = nowy;

				far[tail] = far[head] + 1;

				vis[nowx - 1][nowy] = 1;

			} else {

				dis[x][belong[nowx - 1][nowy]] = min( dis[x][belong[nowx - 1][nowy]], far[head]);

			}

		}

		if (nowy > 1 && !vis[nowx][nowy - 1] && c[nowx][nowy - 1] != '.') {

			if (c[nowx][nowy - 1] == 'S') {

				++tail; if (tail >= 2500000) tail %= 2500000;

				qx[tail] = nowx;

				qy[tail] = nowy - 1;

				far[tail] = far[head] + 1;

				vis[nowx][nowy - 1] = 1;

			} else {

				dis[x][belong[nowx][nowy - 1]] = min( dis[x][belong[nowx][nowy - 1]], far[head]);

			}

		}

		if (nowx < n && !vis[nowx + 1][nowy] && c[nowx + 1][nowy] != '.') {

			if (c[nowx + 1][nowy] == 'S') {

				++tail; if (tail >= 2500000) tail %= 2500000;

				qx[tail] = nowx + 1;

				qy[tail] = nowy;

				far[tail] = far[head] + 1;

				vis[nowx + 1][nowy] = 1;

			} else {

				dis[x][belong[nowx + 1][nowy]] = min( dis[x][belong[nowx + 1][nowy]], far[head]);

			}

		}

		if (nowy < m && !vis[nowx][nowy + 1] && c[nowx][nowy + 1] != '.') {

			if (c[nowx][nowy + 1] == 'S') {

				++tail; if (tail >= 2500000) tail %= 2500000;

				qx[tail] = nowx;

				qy[tail] = nowy + 1;

				far[tail] = far[head] + 1;

				vis[nowx][nowy + 1] = 1;

			} else {

				dis[x][belong[nowx][nowy + 1]] = min( dis[x][belong[nowx][nowy + 1]], far[head]);

			}

		}

	}

}

int main() {

	scanf("%d%d\n", &n, &m);

	for(int i = 1; i <= n; ++i)

		for(int j = 1; j <= m; ++j) {

			c[i][j] = getchar();

			while (c[i][j] != 'X' && c[i][j] != '.' && c[i][j] != 'S')

				c[i][j] = getchar();

		}

	memset(vis, 0, sizeof(vis));

	for(int i = 1; i <= n; ++i)

		for(int j = 1; j <= m; ++j)

			if (!vis[i][j] && c[i][j] == 'X') {

				++cnt;

				_(i, j);

			}

	memset(dis, 1, sizeof(dis));

	for(int i = 1; i <= cnt; ++i) {

		head = 0;

		tail = 0;

		memset(vis, 0, sizeof(vis));

		for(int k = 1; k <= n; ++k)

			for(int l = 1; l <= m; ++l)

				if (belong[k][l] == i) {

					vis[k][l] = 1;

					++tail; if ( tail >= 2500000) tail %= 2500000;

					qx[tail] = k;

					qy[tail] = l;

					far[tail] = 0;

				}

		__(i);

	}

    for(int k = 1; k <= cnt; ++k)

        for(int i = 1; i <= cnt; ++i)

            for(int j = 1; j <= cnt; ++j)

                if (dis[i][k] + dis[k][j] < dis[i][j])

                    dis[i][j] = dis[i][k] + dis[k][j];

	memset(f, 1, sizeof(f));

	int ans = 500000, tot = (1 << cnt) - 1;

	for(int i = 1; i <= cnt; ++i)

		f[1 << ( i - 1)][i] = 0;

	for(int i = 1; i <= tot; ++i) {

		for(int j = 1; 1 << (j - 1) <= i; ++j) {

			if (1 << (j - 1) & i) {

				for(int k = 1; k <= cnt; ++k)

					if (k != j && (1 << (k - 1) & i))

						f[i][j] = min(f[i][j], f[i ^ (1 << (j - 1))][k] + dis[k][j]);

			}

		}

	}

	for(int i = 1; i <= cnt; ++i)

		ans = min(ans, f[tot][i]);

	printf("%d\n",ans);

	return 0;

}