#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll n, h;
using sword = pair<ll, ll>;
int main() {
  cin >> n >> h;
  vector<sword> swords(n);
  for (auto &s : swords) cin >> s.first >> s.second;
  sort(swords.begin(), swords.end(),
       [](sword l, sword r) { return l.second < r.second; });
  auto maxai = 0;
  ll maxa = 0;
  for (auto i = 0; i < n; i++) {
    if (maxa < swords[i].first) {
      maxai = i;
      maxa = swords[i].first;
    }
  }
  auto sumb = 0;
  auto numb = 0;
  for (auto i = 0; i < n; i++) {
    if (swords[i].second > maxa) {
      sumb += swords[i].second;
      numb++;
    }
  }
  auto count = numb;
  h -= sumb;
  count += h / maxa + h % maxa % 1;
  cout << count << endl;
}
