#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  std::vector<int> va;
  std::vector<int> vb;
  int tmp;
  for (int i = 0; i < n; i++) {
    cin >> tmp;
    va.push_back(tmp);
    cin >> tmp;
    vb.push_back(tmp);
  }
  sort(va.begin(), va.end());
  sort(vb.begin(), vb.end());
  int maxa = va[n - 1];
  int over_maxa, maxa_index;
  for (int i = 0; i < n; i++) {
    if (vb[i] > maxa) {
      over_maxa = vb[i];
      maxa_index = i;
      break;
    }
  }
  int result = 0;
  for (int i = maxa_index; i < n; i++) {
    h -= vb[i];
    result++;
  }
  while (h > 0) {
    h -= maxa;
    result++;
  }
  std::cout << result << '\n';
}
