#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];
  int ga = 0, gb = 0, mxa = -1;
  ;
  for (int(i) = 0; (i) < (n); (i)++)
    if (a[i] > ga || (a[i] == ga && b[i] > gb)) {
      mxa = i;
      ga = a[i];
      gb = b[i];
    }
  vector<int> rnk;
  for (int(i) = 0; (i) < (n); (i)++)
    if (i != mxa) rnk.push_back(b[i]);
  sort(rnk.rbegin(), rnk.rend());
  int cr = 0;
  while (1) {
    if (cr < (int)(rnk).size() && rnk[cr] > ga) {
      h -= rnk[cr];
      cr++;
      if (h <= 0) break;
    } else {
      if (gb > ga) {
        h -= gb;
        cr++;
      }
      if (h <= 0) break;
      cr += (h + ga - 1) / ga;
      break;
    }
  }
  cout << cr << "\n";
  return 0;
}
