#include <bits/stdc++.h>
using namespace std;

int n, m;

int main()
{
    cin >> m >> n;
    vector<pair<int, int>> vec;
    for (int i=0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        vec.push_back({u, v});
    }
    sort(vec.begin(), vec.end());
    int k = 1;
    int high = 1;
    int idx = -1;
    vector<int> res;
    for (int i=0; i < vec.size(); i++) {
        if (vec[i].first <= k) {
            if (vec[i].second > high) {
                high = vec[i].second;
                idx = i + 1;
            }
        } else {
            k = high;
            res.push_back(idx);
            i--;
        }
    }
    if (k != n) {
        cout << -1;
        return 0;
    }
    cout << res.size() - 1 << '\n';
    for (int x : res) cout << x << ' ';
    return 0;
}