#include<bits/stdc++.h>
#define int long long
#define endl "\n"
#define ll long long
#define PII std::pair<int,int>
using namespace std;
const int maxn = 1e5 + 5;
signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    cout << fixed << setprecision(2);
    int n, m; cin >> n >> m;
    vector<int> s1, s2;
    for (int i = 1; i <= m; ++i) {
        int u, v; cin >> u >> v;
        if (u > v) s1.push_back(i);
        else s2.push_back(i);
    }
    cout << "YES" << endl;
    if (s1.size() > s2.size()) {
        cout << s1.size() << endl;
        for (auto ss : s1) cout << ss << " ";
    }
    else {
        cout << s2.size() << endl;
        for (auto ss : s2) cout << ss << " ";
    }
    return 0;
}