#include <bits/stdc++.h>
using namespace std;
int main() {
  std::ios::sync_with_stdio(false);
  long long n, h;
  cin >> n >> h;
  vector<long long> u, d;
  u.resize(n);
  d.resize(n);
  long long mx = LLONG_MIN;
  for (long long i = 0; i < n; i++) {
    cin >> u[i] >> d[i];
    if (u[i] > mx) {
      mx = u[i];
    }
  }
  sort(d.begin(), d.end());
  long long ans = 0;
  long long H = h;
  for (long long i = n - 1; i >= 0 && H > 0; i--) {
    if (d[i] >= mx) {
      H -= d[i];
      ans++;
    }
  }
  H = max(0LL, H);
  long long aa = H / mx;
  cout << aa + ans << "\n";
}
