#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  int n;
  int64_t h;
  cin >> n >> h;
  vector<pair<int64_t, int64_t>> vs(n);
  int64_t maxatk = 0;
  for (auto& p : vs) {
    cin >> p.second >> p.first;
    maxatk = max(maxatk, p.second);
  }
  sort(vs.rbegin(), vs.rend());
  int64_t ans = h;
  int64_t sum = 0;
  for (int tc = 0; tc <= n; tc++) {
    int64_t cur = (h - sum + maxatk - 1) / maxatk + tc;
    ans = min(ans, cur);
    if (tc < n) sum += vs[tc].first;
  }
  cout << ans << endl;
  return 0;
}
