#include <bits/stdc++.h>
using namespace std;
#define InTheNameOfGod ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
using ll = long long;

const int maxN = 2e5 + 5;
const int MOD = 1e9 + 7;


vector<vector<int> > g;
vector<int> c;

bool dfs(int x) {
    bool ret = 0;
    for(int sz : g[x]) {
        if(c[sz] == -1) {
            c[sz] = 1 - c[x];
            ret |= dfs(sz);
        }
        else if(c[sz] == c[x]) return true;
    }

    return ret;
}

int main() {
    int t;
    cin >> t;
    while(t--)
    {
        int n,m;
        cin >> n >> m;

        g.clear();
        g.resize(n+1);
        c.assign(n+1, -1);

        for(int i = 0; i < m; i++) {
            int x,y;
            cin >> x >> y;
            x--;
            g[x].push_back(y);
            g[y].push_back(x);
        }

        int comp = 0;
        bool b = 0;
        for(int i = 0; i <= n; i++) {
            if(c[i] == -1) {
                c[i] = 0;
                b |= dfs(i);
                comp++;
            }
        }

        if(b) cout <<"0\n";
        else {
            cout << (1<<(comp-1)) << "\n";
        }
    }
    return 0;
}