#include <algorithm>
#include <iostream>
#include <random>
#include <vector>

using namespace std;

struct Edge {
    int id;
    int fr;
    int to;
};

int main() {
    int n, m;
    cin >> n >> m;
    vector<Edge> edges;
    int left_to_right = 0;
    for (int id = 0; id < m; id++) {
        int fr, to;
        cin >> fr >> to;
        if (fr < to) {
            left_to_right += 1;
        }
        edges.push_back({id, fr, to});
    }
    auto rng = std::default_random_engine(787788);
    shuffle(edges.begin(), edges.end(), rng);
    vector<int> pos(n, -1);
    int used;
    vector<bool> use_edge(m, false);
    for (auto e : edges) {
        if (pos[e.fr] == -1 && pos[e.to] == -1) {
            pos[e.fr] = used;
            used += 1;
            pos[e.to] = used;
            used += 1;
            use_edge[e.id] = true;
        } else if (pos[e.to] == -1) {
            pos[e.to] = used;
            used += 1;
            use_edge[e.id] = true;
        } else if (pos[e.fr] < pos[e.to] && pos[e.fr] != -1) {
            use_edge[e.id] = true;
        }
    }
    cout << "YES\n";
    int cnt_edges = 0;
    for (int i = 0; i < m; i++) {
        if (use_edge[i]) {
            cnt_edges += 1;
        }
    }
    cout << cnt_edges << '\n';
    for (int i = 0; i < m; i++) {
        if (use_edge[i]) {
            cout << (i + 1) << " ";
        }
    }
    cout << '\n';
}