#include <bits/stdc++.h>
using namespace std;
constexpr int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
constexpr int dy[] = {0, -1, 0, 1, 1, -1, -1, 1};
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
  os << "[";
  for (const auto &v : vec) {
    os << v << ",";
  }
  os << "]";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
void solve() {
  int N, H;
  cin >> N >> H;
  vector<int> A(N), B(N);
  priority_queue<int> Q;
  int ma = 0;
  for (int i = 0; i < N; i++) {
    cin >> A[i] >> B[i];
    Q.push(B[i]);
    ma = max(ma, A[i]);
  }
  int cnt = 0;
  while (!Q.empty() && Q.top() > ma) {
    H -= Q.top();
    Q.pop();
    cnt++;
  }
  cnt += (H + ma - 1) / ma;
  cout << cnt << endl;
}
int main() {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);
  cout.setf(ios::fixed);
  cout.precision(16);
  solve();
  return 0;
}
