#include <bits/stdc++.h>
int main(int argc, char const* argv[]) {
  int n, h;
  std::cin >> n >> h;
  int w, t;
  std::vector<int> wList, tList;
  while (std::cin >> w >> t) {
    wList.emplace_back(w);
    tList.emplace_back(t);
  }
  int c = 0;
  for (auto& i : tList) {
    h -= i;
    ++c;
  }
  std::sort(wList.begin(), wList.end());
  c += h / wList.back();
  std::cout << c << std::endl;
  return 0;
}
