#include <bits/stdc++.h>

using namespace std;

long long k,m,n,f;

int main()
{
	cin >> k >> m >> n;
	long long mofazhi,gongjili;
	for(int i = 1;i <= m;i++)
	{
		cin >> mofazhi;
		cin >> gongjili;
		if(k == 0 && gongjili >=0)
		{
			cout << i << ' ';
			f = 1;
		}
		if(mofazhi <= 0 && gongjili != 0)
		{
			cout << i << ' ';
			f = 1;
			break;
		}
		if((k) && (k / mofazhi * gongjili >= n) && (k / mofazhi * gongjili > 0))
		{
			cout << i << ' ';
            f = 1;
		}
	}
    if(f == 0)
    {
        cout << -1;
    }
	return 0;
}

70分三个wa