#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  int a[N];
  int b[N];
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + N);
  sort(b, b + N);
  int maxa = a[N - 1];
  int td = 0;
  int cnt = 0;
  for (int i = 0; i < N; i++) {
    if (b[i] > maxa) {
      td = td + b[i];
      cnt++;
      if (td >= H) {
        cout << cnt << endl;
        return 0;
      }
    }
  }
  if ((H - td) % maxa == 0) {
    cout << cnt + (H - td) / maxa << endl;
    return 0;
  } else
    cout << cnt + (H - td) / maxa + 1 << endl;
  return 0;
}
