#include <bits/stdc++.h>
using namespace std;
const int INF = 2e9;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  for (int i = 0; i < N; i++) cin >> a[i] >> b[i];
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  int ans = INF;
  for (int i = 0; i <= N; i++) {
    if (i > 0) H -= b[i - 1];
    int cnt;
    if (H > 0) cnt = (H + a[0] - 1) / a[0];
    ans = min(ans, i + cnt);
  }
  cout << ans << "\n";
}
