#include <bits/stdc++.h>
using namespace std;
template <class T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
int main() {
  int n, h;
  cin >> n >> h;
  int a, amax = 0;
  vector<int> b(n);
  for (int i = (0); i < (n); ++i) {
    cin >> a >> b[i];
    chmax(amax, a);
  }
  ([&](decltype((b)) whole) {
    return (sort)(begin(whole), end(whole), greater<int>());
  })(b);
  int ans = 0, hp = h, i = 0;
  while (hp > 0 && ans < n) {
    hp -= b[ans];
    ans++;
  }
  if (hp > 0) {
    ans += (hp + amax - 1) / amax;
  }
  cout << ans << endl;
  return 0;
}
