#include <bits/stdc++.h>
using ll = long long;
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ;
  int n;
  ll h;
  cin >> n >> h;
  ll maxx = 0;
  vector<ll> a(n);
  for (int i = 0; i < n; ++i) {
    ll u, v;
    cin >> u >> v;
    a[i] = v;
    maxx = max(maxx, u);
  }
  sort(a.begin(), a.end());
  int ans = 0;
  for (int i = 0; i < n; ++i) {
    if (a[i] / maxx == 0) break;
    h -= a[i];
    ans++;
    if (h <= 0) break;
  }
  if (h <= 0)
    cout << ans;
  else
    cout << ans + (h + maxx - 1) / maxx;
  return 0;
}
