1 #include <cstdio>
 2 #include <algorithm>
 3 #include <queue>
 4 using namespace std;
 5 const int maxn = 100050;
 6 
 7 int f[maxn];
 8 
 9 int sf(int x){ return x == f[x] ? x : f[x] = sf(f[x]); }
10 int main()
11 {
12     int t, n, m, a, b, ans;
13     scanf("%d", &t);
14     while (t--){
15         ans = 0;
16         scanf("%d%d", &n,&m);
17         for (int i = 1; i <= n; i++) f[i] = i;
18         for (int i = 1; i <= m; i++)
19         {
20             scanf("%d%d", &a, &b);
21             f[sf(a)] = sf(b);
22         }
23         for (int i = 1; i <= n; i++)
24             if (f[i] == i)  ans++;
25         printf("%d\n", ans);
26     }
27 }