#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int64_t> a(n), b(n + 1);
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i + 1];
  }
  int64_t max_a = 0;
  for (auto &i : a) max_a = max(max_a, i);
  sort(b.begin() + 1, b.end(), greater<int64_t>());
  for (int i = 1; i <= n; ++i) {
    b[i] += b[i - 1];
  }
  int64_t ans = 1001001001001001001ll;
  for (int i = 0; i <= n; ++i) {
    ans = min(ans, i + (h - b[i] + max_a - 1) / max_a);
  }
  cout << ans << endl;
}
