#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e18;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  for (int i = (int)0; i < (int)N; i++) cin >> a[i] >> b[i];
  sort(a.begin(), a.end(), greater<int>());
  sort(b.begin(), b.end(), greater<int>());
  int rsl = 0;
  for (int i = (int)0; i < (int)N; i++) {
    if (a[0] >= b[i]) break;
    if (H < 0) break;
    H -= b[i];
    rsl++;
  }
  if (H > 0) {
    if (H % a[0] == 0)
      rsl += (H / a[0]);
    else
      rsl += (H / a[0] + 1);
  }
  cout << rsl << endl;
}
