#include <bits/stdc++.h>
using namespace std;
int main() {
  int H, N;
  cin >> N >> H;
  vector<int> A(N), B(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i] >> B[i];
  }
  sort(A.begin(), A.end());
  sort(B.begin(), B.end());
  const int A_max = *max_element(A.begin(), A.end());
  int num = 0;
  int ib = 0;
  while (H > 0) {
    if (B[ib] >= A_max) {
      H -= B[ib];
      ib++;
      num++;
    } else {
      num += H / A_max;
      if (H % A_max) num++;
      break;
    }
  }
  cout << num << endl;
  return 0;
}
