#include <bits/stdc++.h>
using namespace std;
template <class T>
void chmin(T& a, T const& b) {
  if (b < a) a = b;
}
using ll = long long;
const ll mod = LLONG_MAX;
long long N, H;
pair<long long, long long> a[100010];
pair<long long, long long> c[100010];
signed main() {
  cin >> N >> H;
  long long temp = -1e9;
  for (long long i = 0; i < N; i++) {
    cin >> a[i].second >> a[i].first;
    if (temp < a[i].second) temp = a[i].second;
  }
  sort(a, a + N);
  reverse(a, a + N);
  long long idx = 0;
  while (1) {
    if (H < 0 || idx == N || temp > a[idx].first) break;
    H -= a[idx].first;
    idx++;
  }
  if (H <= 0)
    cout << idx << endl;
  else if (H % temp == 0)
    cout << idx + ((H) / temp) << endl;
  else
    cout << idx + ((H) / temp) + 1 << endl;
}
