#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> va(N), vb(N);
  for (int i = 0; i < N; i++) {
    cin >> va.at(i) >> vb.at(i);
  }
  vector<int>::iterator iter = max_element(va.begin(), va.end());
  size_t index = distance(va.begin(), iter);
  int A = va.at(index);
  int B = 0, Bc = 0;
  for (int i = 0; i < N; i++) {
    if (vb.at(i) > A) {
      B += vb.at(i);
      Bc += 1;
    }
  }
  int Ac = (H - B) / A;
  cout << Ac + Bc << endl;
}
