#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll n, h;
  ll answer = 0;
  cin >> n >> h;
  vector<ll> a(n), b(n);
  for (int i = 0; i < (n); ++i) {
    cin >> a[i] >> b[i];
  }
  sort(b.begin(), b.end());
  reverse(b.begin(), b.end());
  ll sum = accumulate(b.begin(), b.end(), 0);
  ll max_a = *max_element(a.begin(), a.end());
  ll x = (h - sum) / max_a;
  h -= x * max_a;
  answer += x;
  while (h > sum) {
    h -= max_a;
    answer++;
  }
  for (int i = 0; i < (n); ++i) {
    h -= b[i];
    answer++;
    if (h <= 0) {
      break;
    }
  }
  cout << answer << endl;
  return 0;
}
