#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n);
  vector<long long> b(n);
  long long a_idx = 0;
  for (long long i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    if (a[i] > a[a_idx]) a_idx = i;
  }
  vector<long long> b_orig = b;
  sort(b.begin(), b.end());
  vector<long long> b_list;
  for (long long i = n - 1; i >= 0; i--) {
    if (b[i] >= a[a_idx]) b_list.push_back(b[i]);
  }
  long long occs = 0;
  long long attcs = 0;
  for (long long i = 0; i < b_list.size(); i++) {
    if (b_list[i] == b_orig[a_idx]) occs++;
    if (b_list[i] != b_orig[a_idx]) {
      h -= b_list[i];
      attcs++;
      if (h <= 0) {
        cout << attcs << endl;
        return 0;
      }
    }
  }
  if (occs > 1) {
    while (occs != 1) {
      h -= b_orig[a_idx];
      attcs++;
      occs--;
      if (h <= 0) {
        cout << attcs << endl;
        return 0;
      }
    }
  }
  long long times;
  if (h > b_orig[a_idx]) {
    times = (h - b_orig[a_idx]) / a[a_idx];
    h -= times * a[a_idx];
    attcs += times;
    if (h <= 0) {
      cout << attcs << endl;
      return 0;
    }
    if (h > b_orig[a_idx]) {
      h -= a[a_idx];
      attcs++;
    }
  }
  attcs++;
  cout << attcs << endl;
  return 0;
}
