#include <bits/stdc++.h>
using namespace std;
int N, H;
vector<pair<int, int>> ab;
int main() {
  scanf("%d %d", &N, &H);
  pair<int, int> katana = make_pair(0, 0);
  for (int i = 0; i < N; ++i) {
    int a, b;
    scanf("%d %d", &a, &b);
    ab.push_back(make_pair(a, b));
    if (a == katana.first && b < katana.second)
      katana = make_pair(a, b);
    else if (a > katana.first)
      katana = make_pair(a, b);
  }
  sort(ab.begin(), ab.end(), [](pair<int, int>& p1, pair<int, int>& p2) {
    return p1.second > p2.second;
  });
  int cnt = 0;
  for (int i = 0; i < ab.size(); ++i) {
    if (ab[i].second < katana.first) break;
    H -= ab[i].second;
    cnt += 1;
    if (H < 0) break;
  }
  cnt += (H + katana.first - 1) / katana.first;
  printf("%d\n", cnt);
  return 0;
}
