#include <iostream>
#include <vector>

using namespace std;

class int2
{
	public:
	int x;
	int y;
};

int main()
{
	int n, m;
	vector<int2> trains;
	vector<int> sol;
	cin >> n >> m;
	int s = 1, e = 1;
	for (int i = 0; i < n; i++)
	{
		int2 in{};
		cin >> in.x >> in.y;
		trains.push_back(in);
	}
	bool found = true;
	while (e != m)
	{
		int max = 0;
		int save = -1;
		int sstart = -1;
		for (int i = 0; i < n; i++)
		{
			if (trains[i].x >= s && trains[i].x <= e)
			{
				if (trains[i].y > max)
				{
					max = trains[i].y;
					sstart = trains[i].x;
					save = i;
				}
			}
		}
		if (save == -1 || max < e)
		{
			found = false;
			break;
		}
		sol.push_back(save + 1);
		s = sstart;
		e = max;
	}
	if (!found)
	{
		cout << -1;
	}
	else
	{
		cout << sol.size() - 1 << endl;
		for (int val : sol)
		{
			cout << val << " ";
		}
		cout << endl;
	}
	return 0;
}