#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int N, H;
  cin >> N >> H;
  int max_a = 0;
  vector<int> b(N, 0);
  for (int i = 0; i < N; i++) {
    int a;
    cin >> a >> b[i];
    max_a = max(max_a, a);
  }
  sort(b.begin(), b.end(), [](const int& l, const int& r) { return l > r; });
  int result = 0;
  for (int e : b) {
    if (e > max_a) {
      H -= e;
      result++;
    } else {
      break;
    }
  }
  if (H > 0) {
    result += (H / max_a) + (H % max_a != 0);
  }
  cout << result;
  return 0;
}
