#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  pair<int, int> A[10000];
  for (int i = 0; i < N; i++) {
    cin >> A[i].second >> A[i].first;
  }
  sort(A, A + N, greater<pair<int, int> >());
  int i = 0, cnt = 0;
  while (A[i].second < A[i + 1].first && H > 0 && i < N - 1) {
    H -= A[i].first;
    i++;
    cnt++;
  }
  H -= A[i].first;
  cnt++;
  cnt += (H + A[i].second - 1) / A[i].second;
  cout << cnt << endl;
  return 0;
}
