#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  int a[100001], b[100001];
  for (int i = 0; i < 100001; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + N);
  reverse(a, a + N);
  sort(b, b + N);
  reverse(b, b + N);
  int cont;
  cont = 0;
  for (int i = 0; i < N + 1; i++) {
    if (b[i] >= a[0] && H > 0) {
      cont += 1;
      H -= b[i];
    }
  }
  cont += (H - 1) / a[0] + 1;
  cout << cont << endl;
}
