1 #include <iostream>
2
3 using namespace std;
4
5 int w, h;
6 int MAP[41][41];
7 int sx, sy, ex, ey;
8 int res;
9 int dx[4] = {
10 1, -1, 0, 0
11 };
12 int dy[4] = {
13 0, 0, 1, -1
14 };
15
16 int runing(int &x, int &y, int dir)
17 {
18 for(;;)
19 {
20 int nx = x + dx[dir];
21 int ny = y + dy[dir];
22 if(nx >= 0 && nx < w && ny >= 0 && ny < h)
23 {
24 if(MAP[ny][nx] == 1)
25 {
26 return 1;
27 }
28 else if(nx == ex && ny == ey)
29 {
30 return 0;
31 }
32 }
33 else
34 {
35 return -1;
36 }
37 x = nx;
38 y = ny;
39 }
40 }
41
42 void dfs(int x, int y, int sum)
43 {
44 int nx, ny;
45 //´óÓÚ10£¬¼ôÖ¦
46 if(sum > 10)
47 return ;
48
49
50 //Ëĸö·½Ïò½øÐÐËÑÑ°
51 for(int i = 0; i < 4; ++i)
52 {
53 nx = x + dx[i];
54 ny = y + dy[i];
55 if(nx >= 0 && nx < w && ny >= 0 && ny < h)
56 {
57 if(MAP[ny][nx] == 1)
58 {
59 continue;
60 }
61 }
62 else
63 continue;
64 nx = x; ny = y;
65 int temp = runing(nx, ny, i);
66 //ÍùÕâ¸ö·½ÏòÅöµ½µÄÊÇǽ
67 if(temp == 1)
68 {
69 MAP[ny+dy[i]][nx+dx[i]] = 0;
70 dfs(nx, ny, sum+1);
71 MAP[ny+dy[i]][nx+dx[i]] = 1;
72
73 }
74 //ÍùÕâ¸ö·½Ïò³ö½çÁË
75 else if(temp == -1)
76 {
77 continue;
78 }
79 //ÍùÕâ¸ö·½Ïòµ½´ïÁËÖÕµã
80 else if(temp == 0)
81 {
82 if(res > sum)
83 res = sum;
84 }
85 }
86
87 }
88
89 void solver()
90 {
91 res = 11;
92 dfs(sx, sy, 1);
93
94 }
95 int main()
96 {
97 while(cin >> w >> h)
98 {
99 if(w == 0 && h == 0)
100 break;
101 //input
102 for(int i = 0; i < h; ++i)
103 {
104 for(int j = 0; j < w; ++j)
105 {
106 cin >> MAP[i][j];
107 if(MAP[i][j] == 2)
108 {
109 sx = j;
110 sy = i;
111 }
112 if(MAP[i][j] == 3)
113 {
114 ex = j;
115 ey = i;
116 }
117 }
118 }
119 //solver
120 solver();
121 //output
122 if(res > 10)
123 cout << -1 << endl;
124 else
125 cout << res << endl;
126 }
127
128 return 0;
129 }
