#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h, maxA = -1, a, b;
  cin >> n >> h;
  vector<int> mb;
  for (int i = 0; i < n; ++i) {
    cin >> a >> b;
    maxA = max(maxA, a);
    mb.push_back(b);
  }
  mb.push_back(maxA);
  sort(mb.begin(), mb.end());
  auto it = find(mb.begin(), mb.end(), maxA);
  int tot = 0, cnt = 0;
  for (auto it2 = it + 1; it2 != mb.end(); ++it2) {
    tot += *it2;
    cnt++;
  }
  h -= tot;
  cout << h / maxA + cnt << endl;
  return 0;
}
