#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<long long> A(N), B(N);
  long long amax = 0;
  for (int i = 0; i < (int)(N); i++) {
    cin >> A[i] >> B[i];
    amax = max(amax, A[i]);
  }
  vector<long long> bv;
  for (int i = 0; i < (int)(N); i++) {
    if (B[i] > amax) {
      bv.push_back(B[i]);
    }
  }
  sort(bv.begin(), bv.end());
  int cnt = 0;
  for (int i = 0; i < (int)(bv.size()); i++) {
    H -= bv[i];
    cnt++;
    if (H <= 0) break;
  }
  if (H > 0) {
    cnt += (H / amax);
    if (H % amax != 0) cnt++;
  }
  cout << cnt << endl;
}
