include <bits/stdc++.h>

using namespace std;

define f(i,a,b) for(int i = a;i <=b;i++)

define int long long

define vi vector

define ve vector

define pii pair<int,int>

define inf 1e9

static constexpr int mod=1e9+7; static constexpr int N = 200;

void fast(){ ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); } vector g[MAXN]; bool was[MAXN];

void dfs(int x){ was[x] = true;

for(int i = 0; i < g[x].size(); i++){
    if (was[g[x][i]] == 0){
        dfs(g[x][i]);
    }
}

}

void solve(){ int n , m; cin >> n >> m; for(int i = 0; i < m; i++){ int x , y; cin >> x >> y; g[x].pb(y); g[y].pb(x); } int ans = 0; for(int i = 1; i < n; i++){ if(!was[i]){ dfs(i); ans++; } } }

signed main() { fast(); int t = 1; cin>>t; while(t--){ solve(); } }