#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
const string ln = "\n";
constexpr int INF = 1001001001;
constexpr int MOD = 1000000007;
int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  ll n, h;
  cin >> n >> h;
  vector<ll> a(n), b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort((b).begin(), (b).end());
  reverse((b).begin(), (b).end());
  ll ma = *max_element((a).begin(), (a).end());
  ll cnt = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] < ma) {
      break;
    }
    h -= b[i];
    cnt++;
    if (h <= 0) {
      break;
    }
  }
  cnt += (h + ma - 1) / ma;
  cout << cnt << endl;
  return 0;
}
