#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using pii = pair<int, int>;
const ll mod = 998244353;

int N, M;
vector<int> graph[200005];
int level[200005];
bool fl;

void init() {
    for (int i = 1; i <= N; i++) graph[i].clear(), level[i] = 0;
    return;
}

void DFS(int node, int par) {
    level[node] = level[par] + 1;
    for (int next: graph[node]) {
        if (level[next]) fl &= (level[node] ^ level[next]) & 1;
        else DFS(next, node);
    }
    return;
}

void solve() {
    cin >> N >> M;
    init();

    for (int i = 0; i < M; i++) {
        int a, b;
        cin >> a >> b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }

    int rk = N;
    for (int i = 1; i <= N; i++) {
        if (!level[i]) fl = 1, DFS(i, 0), rk -= fl;
    }

    ll ans = 1;
    for (int i = 0; i < M - rk; i++) ans *= 5, ans %= mod;

    cout << ans << '\n';

    return;
}

int main(void) {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
#endif
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t = 1;
    cin >> t;
    while (t--) solve();
    return 0;
}