#include <bits/stdc++.h>
int a[10004];
int b[10005];
using namespace std;
int main() {
  int n, y, mx = 0, ans = 0;
  cin >> n >> y;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n);
  mx = a[n - 1];
  for (int j = 0; j < n; j++)
    if ((b[j] >= mx) and (y > 0)) {
      y -= b[j];
      ans++;
    }
  if (y > 0) ans += (y + mx - 1) / mx;
  cout << ans;
  system("pause");
  return 0;
}
