#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  long long maxi = 0, maxi_b;
  for (int i = 0; i < (int)(n); i++) {
    cin >> a.at(i) >> b.at(i);
    if (maxi < a.at(i)) {
      maxi = a.at(i);
      maxi_b = b.at(i);
    }
  }
  sort(b.begin(), b.end());
  reverse(b.begin(), b.end());
  long long is = 0, ans = 0;
  for (long long i = 0; i < n; i++) {
    if (is + b.at(i) >= h) {
      is += b.at(i);
      ans++;
      break;
    }
    if (b.at(i) <= maxi) {
      break;
    }
    is += b.at(i);
    ans++;
    if (is >= h) {
      break;
    }
    if (is + maxi_b >= h) {
      is += maxi_b;
      ans++;
      break;
    }
  }
  long long p = h - is;
  ans += (p + maxi - 1) / maxi;
  cout << ans;
}
