#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
int stoi(const char c) {
  switch (c) {
    case '0':
      return 0;
    case '1':
      return 1;
    case '2':
      return 2;
    case '3':
      return 3;
    case '4':
      return 4;
    case '5':
      return 5;
    case '6':
      return 6;
    case '7':
      return 7;
    case '8':
      return 8;
    case '9':
      return 9;
    default:
      return -1;
  }
}
int main() {
  long long n, h, ans = 0, dmg = 0;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (int i = (int)(0); i < (int)(n); ++i) cin >> a[i] >> b[i];
  sort((a).begin(), (a).end());
  sort((b).begin(), (b).end());
  for (int i = (int)(0); i < (int)(n); ++i) {
    if (b[i] > a[n - 1]) {
      dmg += b[i];
      ans++;
      if (h <= dmg) {
        cout << ans;
        return 0;
      }
    }
  }
  while (dmg < h) {
    dmg += a[n - 1];
    ans++;
  }
  cout << ans;
  return 0;
  return 0;
}
