#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;
}
using ll = long long;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort((a).rbegin(), (a).rend());
  int maxpoint = a[0];
  sort((b).begin(), (b).end());
  int index = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] > maxpoint) {
      index = i;
      break;
    }
  }
  int anscount = 0;
  for (int i = index; i < n; i++) {
    h -= b[i];
    anscount++;
    if (h < 0) {
      cout << anscount << endl;
      return 0;
    }
  }
  while (h > 0) {
    h -= maxpoint;
    anscount++;
  }
  cout << anscount << endl;
  return 0;
}
