#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 10;
vector<int> e[N], num[N];
bool vis[N], vis1[N];
int n, m;
int ans[N];
int s[N];
int d[N];
vector<int> ans2, ans3;
void dfs(int now) {
    // cout<<now<<endl;
    ans[now] = 2;
    vis[now] = 1;
    int tmp = e[now].size();
    for (int i = 0; i < tmp; i++)
        if (!vis[e[now][i]]) {
            ans2.push_back(num[now][i]);
            dfs(e[now][i]);
        } else
            ans3.push_back(num[now][i]);
    return;
}
bool vis2[N];
bool flag;
queue<int> que;
int ifdag[N];
void dfs1(int now) {
    if (ifdag[now])
        return;
    vis2[now] = 1;
    que.push(now);
    int tmp = e[now].size();
    for (int i = 0; i < tmp; i++) {
        if (!vis2[e[now][i]]) {
            dfs1(e[now][i]);
            if (flag)
                return;
        } else {
            flag = true;
            return;
        }
    }
}
int main() {
    int T;
    cin >> T;
    while (T--) {
        cin >> n >> m;
        ans2.clear();
        ans3.clear();
        for (int i = 1; i <= n; i++) {
            vis[i] = 0;
            vis1[i] = 0;
            ans[i] = 0;
            vis2[i] = 0;
            s[i] = 0;
            d[i] = 0;
            e[i].clear();
            num[i].clear();
            ifdag[i] = 0;
        }
        for (int i = 1; i <= m; i++) {
            int l, x, r, y;
            cin >> l >> x >> r >> y;
            if (x > y) {
                swap(l, r);
                swap(x, y);
            }
            vis1[l] = vis1[r] = 1;
            if (x == 2 && y == 2) {
                ans[l] = ans[r] = 2;
                s[l] = 1;
                s[r] = 1;
                ans2.push_back(i);
            }
            if (x == 1 && y == 2) {
                e[l].push_back(r);
                num[l].push_back(i);
                d[r]++;
            }
            if (x == 1 && y == 1)
                ans3.push_back(i);
        }
        for (int i = 1; i <= n; i++) {
            if (s[i] && !vis[i] && vis1[i])
                dfs(i);
        }
        for (int i = 1; i <= n; i++)
            if (d[i] == 0 && !vis[i] && vis1[i]) {
                dfs(i);
                ans[i] = 1;
            }
        vector<int> dfn(n + 1), low(n + 1), bel(n + 1);
        int cur = 0;
        int cnt = 0;
        vector<int> stk;

        auto dfss = [&](auto &&self, int u) -> void {
            dfn[u] = low[u] = ++cur;
            stk.push_back(u);

            for (auto v : e[u]) {
                if (dfn[v] == -1) {
                    self(self, v);
                    low[u] = min(low[u], low[v]);
                } else if (bel[v] == -1) {
                    low[u] = min(low[u], dfn[v]);
                }
            }

            if (dfn[u] == low[u]) {
                int v;
                ++cnt;
                do {
                    v = stk.back();
                    bel[v] = cnt;
                    stk.pop_back();
                } while (v != u);
            }
        };

        for (int i = 1; i <= n; ++i) {
            if (dfn[i] == 0) {
                dfss(dfss, i);
            }
        }

        vector<int> dd(cnt + 1);

        for (int i = 1; i <= n; ++i) {
            for (int v : e[i]) {
                if (bel[i] != bel[v]) {
                    dd[bel[v]]++;
                }
            }
        }

        for (int i = 1; i <= n; i++)
            if (!vis[i] && vis1[i]) {
                flag = false;
                if (dd[bel[i]] == 0) {
                    dfs(i);
                    ans[i] = 1;
                }
            }
        for (int i = 1; i <= n; i++)
            if (vis1[i])
                ans[i] = max(ans[i], 1);
        int ans1 = 0;
        for (int i = 1; i <= n; i++) {
            ans1 += ans[i];
            // cout<<ans[i]<<' ';
        }
        cout << ans1 << endl;
        int tmp = ans3.size();
        for (int i = 0; i < tmp; i++)
            cout << ans3[i] << ' ';
        tmp = ans2.size();
        for (int i = tmp - 1; i >= 0; i--)
            cout << ans2[i] << ' ';
        cout << endl;
    }
    return 0;
}