#include <bits/stdc++.h>
using namespace std;
const int INF = 2e9 + 999;
const long long LINF = 2e18 + 999;
void inv(bool e);
template <typename T>
T sign(T a);
template <typename T>
void die(T &a);
template <typename T>
void umax(T &a, T b);
template <typename T>
void umin(T &a, T b);
bool brute, alter;
int cnt_tests = 1;
int n;
long long H;
vector<pair<long long, long long> > arr;
void inp() {
  cin >> n >> H;
  arr.resize(n);
  for (auto &x : arr) {
    cin >> x.second >> x.first;
  }
}
void solve() {
  sort((arr).rbegin(), (arr).rend());
  pair<long long, long long> mx = {-1, -1};
  int id = -1;
  for (int i = 0; i < n; ++i) {
    if (arr[i].second > mx.second ||
        (arr[i].second == mx.second && arr[i].first > mx.first)) {
      mx = arr[i];
      id = i;
    }
  }
  long long ans = 0;
  long long total = 0;
  for (int i = 0; i < n; ++i) {
    if (total >= H) {
      break;
    }
    if (i == id) {
      continue;
    }
    ++ans;
    total += max(arr[i].first, mx.second);
  }
  if (total >= H) {
    cout << ans;
    return;
  }
  total += max(arr[id].first, arr[id].second);
  ++ans;
  if (total >= H) {
    cout << ans;
    return;
  }
  ans += max(0ll, (H - total + mx.second - 1) / mx.second);
  cout << ans;
}
void stress() {}
void naive() {}
void run();
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  if (0) {
    freopen("palindrome.in", "r", stdin);
    freopen("palindrome.out", "w", stdout);
  }
  srand(time(0));
  brute = false;
  for (int i = 0; (i < cnt_tests); i++) {
    run();
  }
  return 0;
}
void run() {
  if (!brute) {
    inp();
  } else {
    stress();
  }
  solve();
  cout << '\n';
}
template <typename T>
void die(T &a) {
  cout << a;
  exit(0);
}
template <typename T>
T sign(T a) {
  if (a == 0) return 0;
  if (a < 0) return -1;
  return 1;
}
template <typename T>
void umax(T &a, T b) {
  if (b > a) a = b;
}
template <typename T>
void umin(T &a, T b) {
  if (b < a) a = b;
}
void inv(bool e) {
  if (!e) {
    vector<int> a;
    a[-1] += 1;
  }
}
