#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = 2147483647;
const ll MOD = 1000000007;
int main() {
  ll n, h;
  cin >> n >> h;
  vector<ll> a(n);
  vector<ll> b(n);
  for (int i = 0; i < int(n); ++i) {
    cin >> a[i] >> b[i];
  }
  sort(b.begin(), b.end(), greater<ll>());
  sort(a.begin(), a.end(), greater<ll>());
  ll s;
  for (int i = 0; i < int(n); ++i) {
    if (a[0] > b[i]) {
      s = i;
      break;
    }
  }
  int cnt = 0;
  int i = 0;
  while (i < s && i < n) {
    h -= b[i];
    i++;
    cnt++;
    if (h <= 0) break;
  }
  if (h > 0) cnt += h / a[0];
  if (h % a[0]) cnt++;
  cout << cnt << endl;
  return 0;
}
