#include <iostream>
#include <vector>

using namespace std; 

struct vonat
{
    int k, v;
};

int main()
{
    int n, a;
    cin >> n >> a;
    vector <vonat> v(n);
    vector <int> ind;
    
    for (int i = 0; i< n; i++)
    {
        cin >> v[i].k >> v[i].v;
    }
    int vege = 1, i = 0, maxveg, maxind;
    
    while (vege != a)
    {
        maxind = -1;
        maxveg = vege;
        while (i < n && v[i].k <= vege)
        {
            if (v[i].v > maxveg)
            {
                maxveg = v[i].v;
                maxind = i;
            }
            i++;
        }
        if (maxind == -1)
        {
            cout << maxind;
            return 0;
        }
        vege = maxveg;
        ind.push_back (maxind + 1);
    }
    cout << ind.size() - 1 << endl;
    int m = ind.size();
    for (auto i = 0; i < m; i++)
    {
        cout << ind[i] << " ";
    }
    return 0;
}