#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, t, k, kcase;
  long long a, b[100005];
  long long m = 0;
  k = 0;
  kcase = 0;
  cin >> n >> t;
  for (int i = 0; i < n; i++) {
    cin >> a >> b[i];
    if (m < a) {
      m = a;
      k = i;
    } else if (m == a) {
      if (b[k] > b[i]) k = i;
    }
  }
  sort(b, b + n);
  for (int i = n - 1; i >= 0; i--) {
    if (t - b[k] <= 0) {
      cout << kcase + 1 << endl;
      return 0;
    }
    if (i == k) continue;
    if (b[i] > m)
      t = t - b[i];
    else {
      t = t - m;
    }
    kcase++;
    if (t <= 0) {
      cout << kcase << endl;
      return 0;
    }
  }
  t = t - b[k];
  kcase++;
  if (t <= 0)
    cout << kcase << endl;
  else {
    kcase += t / m;
    t = t - (t / m) * m;
    if (t > 0) kcase++;
    cout << kcase << endl;
  }
  return 0;
}
