#include <bits/stdc++.h>
using namespace std;
const int N = 3e5 + 500;
const long long mod = 1e9 + 7;
const long long cmod = 998244353;
const long long inf = 1LL << 61;
const int M = 1e6 + 500;
const long long int ths = 1LL << 40;
const int NN = 5e3 + 6;
void solve() {
  long long int n, H;
  cin >> n >> H;
  long long int a[n];
  long long int b[n];
  vector<pair<long long int, long long int> > v, v2;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    v.push_back({a[i], i});
    v2.push_back({b[i], i});
  }
  sort(v.rbegin(), v.rend());
  sort(v2.rbegin(), v2.rend());
  long long int ans = 0;
  for (int i = 0; i < n; i++) {
    if (H <= 0) break;
    if (b[i] > v[0].first) {
      H -= b[i];
      ans++;
    }
  }
  H = max(H, 0LL);
  ans += ceil((long double)H / v[0].first);
  cout << ans;
  cout << "\n";
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
