1 #include <map>
 2 #include <stack>
 3 #include <queue>
 4 #include <math.h>
 5 #include <stdio.h>
 6 #include <string.h>
 7 #include <iostream>
 8 #include <limits.h>
 9 #include <algorithm>
10 #define LL long long
11 #define min(a,b) (a>b?b:a)
12 #define max(a,b) (a>b?a:b)
13 #define eps 1e-9
14 #define INF 1 << 30
15 using namespace std;
16
17 bool vis[30][30], output;
18 int Num;
19 char path[120];
20 int dx[8] = {-2, -2, -1, -1, 1, 1, 2, 2};
21 int dy[8] = {-1, 1, -2, 2, -2, 2, -1, 1};
22 int a, b;
23
24 void Dfs(int depth, int x, int y)
25 {
26     if(depth == Num)
27     {
28         for(int i = 0; i < 2*depth; i++)
29             printf("%c", path[i]);
30         printf("\n\n");
31         output = true;
32         return ;
33     }
34     for(int i = 0; i < 8 && output == false; i++)
35     {
36         int new_x = x+dx[i];
37         int new_y = y+dy[i];
38         if(new_x >= 1 && new_x <= b && new_y >= 1 && new_y <= a && vis[new_y][new_x] == false)
39         {
40             vis[new_y][new_x] = true;
41             path[2*depth] = 'A'+new_x-1;
42             path[2*depth+1] = '1'+new_y-1;
43             Dfs(depth+1, new_x, new_y);
44             vis[new_y][new_x] = false;
45         }
46     }
47 }
48
49 void run()
50 {
51     int n;
52     scanf("%d", &n);
53     for(int p = 1; p <= n; p++)
54     {
55         scanf("%d%d", &a, &b);
56         printf("Scenario #%d:\n", p);
57         for(int i = 1; i <= a; i++)
58             for(int j = 1; j <= b; j++)
59                 vis[i][j] = false;
60         Num = a*b;
61         output = false;
62         vis[1][1] = true;
63         path[0] = 'A';
64         path[1] = '1';
65         Dfs(1, 1, 1);
66         if(output == false)
67             printf("impossible\n\n");
68     }
69 }
70
71 int main(void)
72 {
73     run();
74
75     return 0;
76 }