#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, h;
  cin >> n >> h;
  vector<pair<int, int>> b(n);
  pair<int, int> a = {-1, -1};
  for (int i = 0; i < n; i++) {
    int x, y;
    cin >> x >> y;
    if (x > a.first || (x == a.first && y < b[a.second].first)) {
      a = {x, i};
    }
    b[i] = {y, i};
  }
  sort((b).begin(), (b).end());
  long long ans = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (h <= 0 || b[i].first <= a.first) break;
    if (b[i].second != a.second) {
      h -= b[i].first;
      ans++;
    }
  }
  if (h > 0) {
    if (b[a.second].first > a.first) {
      h -= b[a.second].first;
      ans++;
    }
    if (h > 0) {
      ans += h / a.first + (h % a.first != 0);
    }
  }
  cout << ans << '\n';
  return 0;
}
