#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
  int n, m;
  cin >> n >> m;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
  vector<int> d(n);
  for (int i = 0; i < n; ++i) d[i] = (m - a[i]) / b[i];
  sort(d.begin(), d.end());
  int l = 0, r = n + 1;
  while (r - l > 1)
  {
    int mid = (l + r) / 2, flag = 1;
    for (int i = 0; i * mid < n; ++i)
    {
      for (int j = 0; j < mid; ++j)
      {
        if (i * mid + j >= n) break;
        if (d[i * mid + j] < i)
        {
          flag = 0;
        }
      }
    }
    (flag ? r : l) = mid;
  }
  cout << r << endl;
}