1 #include<cstdio>
 2 #include<cstring>
 3 #include<queue>
 4 #include<algorithm>
 5 using namespace std;
 6
 7 const int INF = 1000000000;
 8 const int maxr = 25 + 5;
 9 const int maxc = 25 + 5;
10 int R, C, sr, sc, tr, tc;
11 char maze[maxr][maxc];
12
13 struct State {
14     int r, c, dir, color;
15     State(int r, int c, int dir, int color):r(r),c(c),dir(dir),color(color) {}
16 };
17
18 const int dr[] = {-1,0,1,0}; // north, west, south, east
19 const int dc[] = {0,-1,0,1};
20 int d[maxr][maxc][4][5], vis[maxr][maxc][4][5];//横坐标,纵坐标,方向,颜色
21
22 int ans;
23 queue<State> Q;
24
25 void update(int r, int c, int dir, int color, int v) {
26     if(r < 0 || r >= R || c < 0 || c >= C) return; // 不能走出边界
27     if(maze[r][c] == '.' && !vis[r][c][dir][color]) {
28         Q.push(State(r, c, dir, color));
29         vis[r][c][dir][color] = 1;
30         d[r][c][dir][color] = v;
31         if(r == tr && c == tc && color == 0) ans = min(ans, v); // 更新答案
32     }
33 }
34
35 void bfs(State st) {
36     d[st.r][st.c][st.dir][st.color] = 0;
37     vis[st.r][st.c][st.dir][st.color] = 1;
38     Q.push(st);
39     while(!Q.empty()) {
40         st = Q.front();
41         Q.pop();
42         int v = d[st.r][st.c][st.dir][st.color] + 1;
43         update(st.r, st.c, (st.dir+1)%4, st.color, v); // 左转
44         update(st.r, st.c, (st.dir+3)%4, st.color, v); // 右转
45         update(st.r+dr[st.dir], st.c+dc[st.dir], st.dir, (st.color+1)%5, v); // 前进
46     }
47 }
48
49 int main() {
50     int kase = 0;
51     while(scanf("%d%d", &R, &C) == 2 && R && C) {
52         for(int i = 0; i < R; i++) {
53             scanf("%s", maze[i]);
54             for(int j = 0; j < C; j++)
55                 if(maze[i][j] == 'S') {
56                     sr = i;
57                     sc = j;
58                 } else if(maze[i][j] == 'T') {
59                     tr = i;
60                     tc = j;
61                 }
62         }
63         maze[sr][sc] = maze[tr][tc] = '.';
64         ans = INF;
65         memset(vis, 0, sizeof(vis));
66         bfs(State(sr, sc, 0, 0));
67
68         if(kase > 0) printf("\n");
69         printf("Case #%d\n", ++kase);
70         if(ans == INF) printf("destination not reachable\n");
71         else printf("minimum time = %d sec\n", ans);
72     }
73 }