#include <bits/stdc++.h>

using namespace std;

using ll = long long;

template <class T>
T smax(T & x, T y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}

template <class T>
T smin(T & x, T y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}


void solve() {
    int n, m;
    cin >> n >> m;
    cout << "YES\n";
    vector<int> forward;
    vector<int> backward;
    for (int i = 0; i < m; ++i) {
        int a, b;
        cin >> a >> b;
        if (a < b) {
            forward.push_back(i + 1);
        } else {
            backward.push_back(i + 1);
        }
    }
    if (forward.size() >= backward.size()) {
        cout << forward.size() << "\n";
        for (auto i : forward) {
            cout << i << " ";
        }
    } else {
        cout << backward.size() << "\n";
        for (auto i : backward) {
            cout << i << " ";
        }
    }
    cout << "\n";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t = 1;
//    cin >> t;
    cout << fixed << setprecision(14);
    while (t--) {
        solve();
    }
    cerr << clock() * 1.0 / CLOCKS_PER_SEC << "\n";
    return 0;
}