#include <bits/stdc++.h>
using namespace std;
const int64_t mod = 1e9 + 7;
void dbg() { cerr << "\n"; }
template <typename T, typename... T2>
void dbg(const T& fst, const T2&... rst) {
  cerr << fst << ": ";
  dbg(rst...);
}
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int(i) = 0; (i) < (n); (i)++) cin >> a[i] >> b[i];
  sort(b.rbegin(), b.rend());
  int ga = *max_element((a).begin(), (a).end());
  int cr = 0;
  for (int(i) = 0; (i) < (n); (i)++) {
    if (b[i] > ga) {
      h -= b[i];
      cr++;
      if (h <= 0) break;
    } else {
      cr += (h + ga - 1) / ga;
      break;
    }
  }
  cout << cr << "\n";
  return 0;
}
