#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const long long INF = 1e12;
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (long long i = 0; i < n; i++) cin >> a[i] >> b[i];
  long long ans = 0;
  sort(a.begin(), a.end());
  reverse(a.begin(), a.end());
  sort(b.begin(), b.end());
  reverse(b.begin(), b.end());
  for (long long i = 0; i < n; i++) {
    if (b[i] > a[0]) {
      h -= b[i];
      ans++;
      if (h < 0) break;
    }
  }
  cout << ans + (h + a[0] - 1) / a[0] << endl;
}
