#include <bits/stdc++.h>
using namespace std;
signed main() {
  int64_t n, h;
  cin >> n >> h;
  vector<int64_t> a(n), b(n);
  for (int64_t i = 0; i < n; ++i) cin >> a[i] >> b[i];
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  int64_t ans = 0;
  while (h && !b.empty() && b.back() >= a.back()) {
    h -= b.back();
    b.pop_back();
    ++ans;
  }
  ans += (h + a.back() - 1) / a.back();
  cout << ans << '\n';
}
