1 #include <cstdio>
 2 #include <cstring>
 3 
 4 
 5 int pu[100000000], pv[100000000];
 6 
 7 int white[10], black[10], deg[10];
 8 
 9 int p[30];
10 int t, n, m;
11 
12 int main() {
13     
14     for (int i = 1; i <= 28; i++) p[i] = 1 << i;
15     scanf("%d", &t);
16     while (t--) {
17         memset(deg, 0, sizeof(deg));
18         scanf("%d%d", &n, &m);
19         for (int i = 1; i <= m; i++) {
20             scanf("%d%d", &pu[i], &pv[i]);
21             deg[pu[i]]++;
22             deg[pv[i]]++;
23         }
24         bool ok = true;
25         for (int i = 1; i <= n; i++) {
26             if (deg[i]&1) {
27                 ok = false;
28                 break;
29             }
30         }
31         if (!ok) {
32             puts("0");
33             continue;
34         }
35         int maxlen = 1 << m;
36         int ans = 0;
37         for (int i = 0; i <= maxlen; i++) {
38             for (int j = 1; j <= m; j++) {
39                 if (i & p[j]) {
40                     black[pu[j]]++;
41                     black[pv[j]]++;
42                 } else {
43                     white[pu[j]]++;
44                     white[pv[j]]++;
45                 }
46             }
47             ok = true;
48             for (int i = 1; i <= n; i++) {
49                 if (black[i] != white[i]) {
50                     ok = false;
51                     break;
52                 }
53             }
54             if (ok) ans++;
55             memset(black, 0, sizeof(black));
56             memset(white, 0, sizeof(white));
57         }
58         printf("%d\n", ans);
59     }
60     return 0;
61 }