#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  int m = *max_element(a.begin(), a.end());
  queue<int> q;
  for (int i = 0; i < n; i++)
    if (b[i] > m) q.push(b[i]);
  int ans = 0;
  while (!q.empty()) {
    h -= q.front();
    ans++;
    q.pop();
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
  while (h > 0) {
    h -= m;
    ans++;
  }
  cout << ans << endl;
  return 0;
}
