#include <bits/stdc++.h>
template <typename T>
void MACRO_VAR_Scan(T& t) {
  std::cin >> t;
}
template <typename First, typename... Rest>
void MACRO_VAR_Scan(First& first, Rest&... rest) {
  std::cin >> first;
  MACRO_VAR_Scan(rest...);
}
template <typename T>
void MACRO_VEC_ROW_Init(int n, T& t) {
  t.resize(n);
}
template <typename First, typename... Rest>
void MACRO_VEC_ROW_Init(int n, First& first, Rest&... rest) {
  first.resize(n);
  MACRO_VEC_ROW_Init(n, rest...);
}
template <typename T>
void MACRO_VEC_ROW_Scan(int p, T& t) {
  std::cin >> t[p];
}
template <typename First, typename... Rest>
void MACRO_VEC_ROW_Scan(int p, First& first, Rest&... rest) {
  std::cin >> first[p];
  MACRO_VEC_ROW_Scan(p, rest...);
}
template <typename T>
inline T CHMAX(T& a, const T b) {
  return a = (a < b) ? b : a;
}
template <typename T>
inline T CHMIN(T& a, const T b) {
  return a = (a > b) ? b : a;
}
void CHECKTIME(std::function<void()> f) {
  auto start = std::chrono::system_clock::now();
  f();
  auto end = std::chrono::system_clock::now();
  auto res = std::chrono::duration_cast<std::chrono::nanoseconds>((end - start))
                 .count();
  std::cerr << "[Time:" << res << "ns  (" << res / (1.0e9) << "s)]\n";
}
template <class T>
std::vector<std::vector<T>> VV(int n) {
  return std::vector<std::vector<T>>(n);
}
template <class T>
std::vector<std::vector<T>> VV(int n, int m, T init = T()) {
  return std::vector<std::vector<T>>(n, std::vector<T>(m, init));
}
template <typename S, typename T>
std::ostream& operator<<(std::ostream& os, std::pair<S, T> p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using PAIR = std::pair<int, int>;
using PAIRLL = std::pair<ll, ll>;
constexpr int INFINT = 1 << 30;
constexpr int INFINT_LIM = (1LL << 31) - 1;
constexpr ll INFLL = 1LL << 60;
constexpr ll INFLL_LIM = (1LL << 62) - 1 + (1LL << 62);
constexpr double EPS = 1e-9;
constexpr int MOD = 1000000007;
constexpr double PI = 3.141592653589793238462643383279;
signed main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  ;
  int n, h;
  MACRO_VAR_Scan(n, h);
  ;
  std::vector<int> a, b;
  MACRO_VEC_ROW_Init(n, a, b);
  for (int i = 0; i < n; ++i) {
    MACRO_VEC_ROW_Scan(i, a, b);
  };
  int max = 0, max_i = 0;
  for (int i = 0; i < int(n); ++i) {
    if (max < a[i]) {
      max = a[i];
      max_i = i;
    }
  }
  std::priority_queue<int> pq;
  for (int i = 0; i < int(n); ++i) {
    if (i != max_i) pq.push(b[i]);
  }
  int ans = 0;
  while (h > 0) {
    int now = 0;
    if (!pq.empty()) {
      now = pq.top();
      pq.pop();
    }
    if (now <= max) {
      int top = std::max(now, b[max_i]);
      h -= top;
      ++ans;
      int t = (h + max - 1) / max;
      ans += t;
      std::cout << ans;
      std::cout << "\n";
      ;
      return 0;
    }
    h -= now;
    ++ans;
  }
  std::cout << ans;
  std::cout << "\n";
  ;
  return 0;
}
