#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using plong = pair<ll, ll>;
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
const long MOD = 1000000007;
int main() {
  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());
  ll max_a = a[N - 1];
  ll res = 0;
  for (ll i = 0; i < N; i++) {
    if (max_a < b[N - 1 - i]) {
      res++;
      H -= b[N - 1 - i];
    } else {
      break;
    }
  }
  res += ceil((double)H / max_a);
  cout << res << endl;
}
