#include <bits/stdc++.h>
using namespace std;
using ll = long long;
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() {
  ios::sync_with_stdio(false);
  ll n, h;
  cin >> n >> h;
  vector<ll> a(n), b(n);
  for (ll i = 0; i < (n); ++i) cin >> a[i] >> b[i];
  sort(a.begin(), a.end());
  sort(b.begin(), b.end(), greater<ll>());
  ll a_max = a.back();
  ll cnt = 0;
  for (ll i = 0; i < (n); ++i) {
    if (b[i] <= a_max) break;
    if (h <= 0) break;
    cnt++;
    h -= b[i];
  }
  cnt += (h + a_max - 1) / a_max;
  cout << cnt << endl;
}
