#include <bits/stdc++.h>
int a[10004];
int b[10005];
int n, y, mx, ans;
using namespace std;
int main() {
  cin >> n >> y;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n, greater<int>());
  mx = a[0];
  sort(b, b + n, greater<int>());
  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;
}
