#include <bits/stdc++.h>
using namespace std;
int main() {
  long long M, f, g, p, N, H, count;
  cin >> N >> H;
  count = 0;
  vector<long long> a(N), b(N);
  vector<pair<long long, long long>> S(N);
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    S[i] = make_pair(a[i], b[i]);
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  sort(S.begin(), S.end());
  reverse(a.begin(), a.end());
  reverse(b.begin(), b.end());
  reverse(S.begin(), S.end());
  p = S[0].second;
  for (int i = 0; i < N; i++) {
    if (b[i] > a[0] && S[0].second != b[i]) {
      count++;
      H -= b[i];
    } else if (b[i] > a[0] && S[0].second == b[i]) {
      S[0].second = 0;
      continue;
    } else if (b[i] <= a[0]) {
      break;
    }
    if (H <= 0) {
      cout << count << endl;
      return 0;
    }
  }
  H -= p;
  count++;
  if (H <= 0) {
    cout << count << endl;
    return 0;
  }
  count += H / a[0];
  if (H % a[0] == 0) {
    cout << count << endl;
    return 0;
  } else {
    count++;
    cout << count << endl;
    return 0;
  }
}
