#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  int aa, bb;
  vector<int> b;
  int ma = 0;
  int cnt = 0;
  cin >> n >> h;
  for (int i = 0, i_len = (n); i < i_len; ++i) {
    cin >> aa >> bb;
    if (ma < aa) ma = aa;
    b.push_back(bb);
  }
  sort((b.begin()), (b.end()), greater<int>());
  for (int i = 0, i_len = (n); i < i_len; ++i) {
    if (ma < b[i]) {
      h -= b[i];
      b[i] = 0;
    }
    if (h < 0) break;
  }
  cout << cnt + (h + ma - 1) / ma << "\n";
  return 0;
}
