#include <bits/stdc++.h>
using namespace std;
int dy[] = {0, 0, 1, -1, 0};
int dx[] = {1, -1, 0, 0, 0};
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long N, H;
  cin >> N >> H;
  vector<long long> a(N), b(N);
  long long a_max = 0;
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    a_max = max(a_max, a[i]);
  }
  sort(b.rbegin(), b.rbegin());
  long long ans = 0;
  for (int i = 0; i < N; i++) {
    if (b[i] >= a_max) ans++, H -= b[i];
  }
  while (H > 0) {
    H -= a_max;
    ans++;
  }
  cout << ans << endl;
}
