#include <bits/stdc++.h>
using namespace std;
template <class t, class u>
void cmax(t& a, u b) {
  if (a < b) a = b;
}
template <class t, class u>
void cmin(t& a, u b) {
  if (a > b) a = b;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  int max_a = 0;
  for (long long i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    if (max_a < a[i]) {
      max_a = a[i];
    }
  }
  sort(b.rbegin(), b.rend());
  int ans = 0;
  for (long long i = 0; i < n; i++) {
    if (b[i] < max_a) break;
    ans++;
    h -= b[i];
    if (h < 0) {
      cout << ans << endl;
      return 0;
    }
  }
  cout << ans + (h - 1) / max_a + 1 << endl;
}
