#include <bits/stdc++.h>
using namespace std;
template <typename T = long long>
inline T IN() {
  T x;
  cin >> x;
  return (x);
}
inline void CIN() {}
template <class Head, class... Tail>
inline void CIN(Head &&head, Tail &&...tail) {
  cin >> head;
  CIN(move(tail)...);
}
template <typename T = string>
inline void eputs(T s) {
  cout << s << "\n";
  exit(0);
}
template <typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val) {
  std::fill((T *)array, (T *)(array + N), val);
}
template <typename T>
using PQG = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
using PQ = priority_queue<T>;
const long long INF = 1e9;
const long long MOD = 1e9 + 7;
const long long LINF = 1e18 + 1;
const long long dx[] = {1, -1, 0, 0};
const long long dy[] = {0, 0, 1, -1};
long long N, H;
vector<long long> a, b;
signed main() {
  cin >> N >> H;
  for (long long i = 0; i < (N); ++i) {
    a.emplace_back(IN());
    b.emplace_back(IN());
  }
  sort((b).begin(), (b).end(), greater<long long>());
  long long slash = *max_element((a).begin(), (a).end());
  long long sum = 0, thr = 0;
  for (long long i = 0; i < (N); ++i) {
    if (b[i] <= slash) {
      thr = i;
      break;
    }
    sum += b[i];
    if (i == N - 1) {
      thr = N;
      break;
    }
  }
  long long ans = (H - sum) / slash + thr;
  if ((H - sum) % slash) ans++;
  cout << ans << "\n";
}
