#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
};
template <class T>
inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
};
int main() {
  int N, H;
  cin >> N >> H;
  int h = H;
  vector<pair<int, int> > sords(N);
  int a, b;
  int ma, mb;
  ma = mb = 0;
  pair<int, int> masord = {0, 0};
  int masord_idx;
  for (int i = (int)0; i < (int)N; i++) {
    cin >> a >> b;
    if (a >= h || b >= h) {
      cout << 1 << endl;
      return 0;
    }
    if (a >= ma && b > masord.second) {
      masord = {a, b};
      masord_idx = i;
    }
    ma = max(ma, a);
    mb = max(mb, b);
    sords[i].first = a;
    sords[i].second = b;
  }
  int ans = 0;
  for (int i = (int)0; i < (int)N; i++) {
    if (i == masord_idx) continue;
    auto sord = sords[i];
    a = sord.first;
    b = sord.second;
    if (b > ma) {
      ans += 1;
      H -= b;
      if (H <= 0) {
        cout << ans << endl;
        return 0;
      }
    }
  }
  if (masord.first >= masord.second) {
    ans += (H + masord.first - 1) / masord.first;
    cout << ans << endl;
    return 0;
  } else {
    ans += 1;
    H -= masord.second;
    if (H <= 0) {
      cout << ans << endl;
      return 0;
    } else {
      ans += (H + masord.first - 1) / masord.first;
      cout << ans << endl;
      return 0;
    }
  }
  return 0;
};
