#include <bits/stdc++.h>
const double PI =
    3.141592653589793238462643383279502884197169399375105820974944;
using namespace std;
void solve() {
  long long n, h;
  cin >> n >> h;
  vector<pair<long long, long long> > vec(n);
  long long sum = 0;
  for (long long i = 0; i < n; ++i) {
    long long a, b;
    cin >> a >> b;
    vec[i] = make_pair(a, b);
    sum += b;
  }
  sort(vec.begin(), vec.end());
  printf("%.0f\n", min(ceil(((h - sum) * 1.0) / (1.0 * vec[n - 1].first)),
                       ceil((h - sum) * 1.0) / (vec[n - 1].first * 1.0)) +
                       n);
}
int main() {
  bool testing = false;
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  if (testing) {
    freopen("test.txt", "rt", stdin);
    int start = clock();
    solve();
    int end = clock();
    cout << "time: " << (end - start) / (double)(CLOCKS_PER_SEC)*1000
         << " milliseconds\n";
  } else {
    solve();
  }
}
