#include <bits/stdc++.h>
using namespace std;
typedef vector<vector<int>> vii;
template <typename T>
using vec = vector<T>;
template <class T>
using maxheap = std::priority_queue<T>;
template <class T>
using minheap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template <class T, class U>
inline bool chmax(T &a, const U &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U>
inline bool chmin(T &a, const U &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
const long double Pi = std::acos(-1.0L);
const long long infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;
const int mod = 1000000007;
signed main() {
  int START_TIME = clock();
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < ((int)(n)); i++) cin >> a[i] >> b[i];
  sort(b.rbegin(), b.rend());
  sort(a.rbegin(), a.rend());
  vector<long long> csum(n + 1);
  for (int i = 0; i < ((int)(n)); i++) csum[i + 1] += csum[i] + b[i];
  long long ans = infll, times;
  for (int i = 0; i < n; ++i) {
    times = i + 1;
    long long H = h - (csum[i + 1] - csum[0]);
    times += (H + a[0] - 1) / a[0];
    chmin(ans, times);
  }
  cout << ans << '\n';
}
