#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  vector<int> throwing(n);
  vector<int> attacking(n);
  for (int i = 0; i < n; ++i) cin >> attacking[i] >> throwing[i];
  sort(throwing.begin(), throwing.end(), greater<int>());
  sort(attacking.begin(), attacking.end(), greater<int>());
  int a = n;
  int dmg = 0;
  for (int i = 0; i < throwing.size(); ++i) {
    if (attacking[0] > throwing[i]) {
      a = i;
      break;
    }
    dmg += throwing[i];
  }
  int howmany = (h - dmg) / attacking[0];
  if ((h - dmg) % attacking[0] > 0) howmany++;
  howmany += a;
  cout << howmany << endl;
  return 0;
}
