#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  int temp_h = h;
  vector<pair<int, int>> ab;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    ab.push_back(make_pair(a, b));
  }
  sort(ab.begin(), ab.end(), greater<pair<int, int>>());
  int cnt = 0;
  while (h > 0 && cnt < n) {
    h -= ab[cnt].second;
    cnt++;
  }
  if (h > 0) {
    cnt += (h + ab[0].first - 1) / ab[0].first;
  }
  cnt = min(cnt, (temp_h - ab[0].second + ab[0].first - 1) / ab[0].first + 1);
  cout << cnt << endl;
}
