#include <bits/stdc++.h>
using namespace std;
using lint = long long;
const int INF = 1e9;
const lint LINF = 1e18;
const lint MOD = 1e9 + 7;
const double EPS = 1e-10;
int main() {
  int n, h;
  cin >> n >> h;
  vector<pair<lint, lint>> a(n);
  for (int i = (int)(0); i < (int)(n); i++) {
    cin >> a[i].first >> a[i].second;
  }
  sort(a.begin(), a.end());
  reverse(a.begin(), a.end());
  int s = a[0].first;
  vector<lint> sub(0);
  for (int i = 0; i < a.size(); i++) {
    if (s < a[i].second) {
      sub.push_back(a[i].second);
    } else {
      continue;
    }
  }
  sort(sub.begin(), sub.end());
  reverse(sub.begin(), sub.end());
  lint ans = 0;
  vector<lint> L(sub.size() + 1, 0);
  for (int i = 0; i < n; i++) {
    L[i + 1] = L[i] + sub[i];
  }
  int idx = lower_bound(L.begin(), L.end(), h) - L.begin();
  cerr << "sub"
          ":[ ";
  for (auto macro_vi : sub) {
    cerr << macro_vi << " ";
  }
  cerr << "]" << endl;
  ;
  cerr << "L"
          ":[ ";
  for (auto macro_vi : L) {
    cerr << macro_vi << " ";
  }
  cerr << "]" << endl;
  ;
  cerr << "idx"
          ":"
       << idx << endl;
  ;
  if (idx == L.size()) {
    ans = idx - 1;
    h -= L.back();
    ans += (h + s - 1) / s;
  } else {
    ans = idx + 1;
  }
  cout << ans << endl;
  return 0;
}
