#include <bits/stdc++.h>
using namespace std;
vector<pair<long long, long long> > v;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n, h, i, ans = 0, a, b;
  cin >> n >> h;
  for (i = 0; i < n; i++) {
    cin >> a >> b;
    v.push_back(make_pair(a, 1));
    v.push_back(make_pair(b, 0));
  }
  sort(v.rbegin(), v.rend());
  for (i = 0; i < 2 * n; i++) {
    if (v[i].second == 1)
      break;
    else
      h -= v[i].first;
  }
  ans = i;
  ans += (h + v[i].first - 1) / v[i].first;
  cout << ans << "\n";
  return 0;
}
