#include <bits/stdc++.h>

using namespace std;
#define ll long long
#define pii pair<int, int>
#define ld long double
#define all(a) (a).begin(), (a).end()

const int MAXN = 5e5 + 100;
vector<array<int, 2>> g[MAXN];
vector<int> e[MAXN];
int used[MAXN], res[MAXN];

vector<int> ans;

void dfs(int v) {
    used[v] = true;
    for (auto e : g[v]) {
        int u = e[0], id = e[1];
        if (!used[u]) {
            dfs(u);
        }
        res[u] = 2;
        res[v] = 1;
        ans.push_back(id);
    }
}

vector<int> top;

void build_top(int v) {
    used[v] = true;
    for (int u : e[v]) {
        if (!used[u]) {
            build_top(u);
        }
    }
    top.push_back(v);
}

int col[MAXN];
int is_start[MAXN];

void color(int v, int c) {
    col[v] = c;
    for (auto e : g[v]) {
        int u = e[0];
        if (col[u] == 0) {
            color(u, c);
        } else if (col[u] != c) {
            is_start[col[u]] = 0;
        }
    }
}

void solve() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; ++i) {
        g[i].clear();
    }
    ans.clear();
    fill(used, used + n, 0);
    fill(res, res + n, 0);
    vector<int> good;
    vector<int> start, fin;
    for (int i = 0; i < m; ++i) {
        int u, v, x, y;
        cin >> u >> x >> v >> y;
        x--; y--;
        u--; v--;
        if (x + y == 0) {
            start.push_back(i);
            res[u] = res[v] = 1;
            continue;
        }
        if (x + y == 2) {
            fin.push_back(i);
            good.push_back(u);
            good.push_back(v);
            continue;
        }
        if (x == 1) {
            swap(u, v);
        }
        g[u].push_back({v, i});
        e[v].push_back(u);
    }

    top.clear();
    for (int i = 0; i < n; ++i) {
        if (!used[i]) {
            build_top(i);
        } 
    }
    reverse(top.begin(), top.end());
    int c = 1;
    fill(col, col + n, 0);
    for (int i : top) {
        if (col[i] == 0) {
            is_start[c] = 1;
            color(i, c++);
        }
    }

    fill(used, used + n, 0);
    for (int v : good) {
        if (!used[v]) {
            dfs(v);
        }
    }
    for (int i = 0; i < n; ++i) {
        if (!used[i] && is_start[col[i]]) {
            dfs(i);
        }
    }
    for (int v : good) {
        res[v] = 2;
    }
    int sum = 0;
    for (int i = 0; i < n; ++i) {
        sum += res[i];
    }
    cout << sum << "\n";
    for (int i : start) {
        cout << i + 1 << " ";
    }
    for (int i : ans) {
        cout << i + 1 << " ";
    }
    for (int i : fin) {
        cout << i + 1 << " ";
    }
    cout << "\n";
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int tst;
    cin >> tst;
    while (tst--) {
        solve();
    }

    return 0;
}