#include <bits/stdc++.h>
using namespace std;
const int IINF = 1e9;
const long long LINF = 1e18;
const long long mod = 1e9 + 7;
int main() {
  long long N, H;
  cin >> N >> H;
  vector<long long> a(N);
  vector<long long> b(N);
  for (int i = 0; i < (int)(N); i++) {
    cin >> a[i] >> b[i];
  }
  long long A = *max_element((a).begin(), (a).end());
  sort((b).begin(), (b).end(), greater<long long>());
  long long t = 0;
  long long res = (H + A - 1) / A;
  for (int i = 0; i < (int)(N); i++) {
    t += b[i];
    long long c = i + 1 + (H - t + A - 1) / A;
    res = max<long long>(min(res, c), 0);
  }
  cout << res << endl;
  return 0;
}
