#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 10000;
long long b[MAX_N];
int main() {
  int n;
  long long h;
  cin >> n >> h;
  long long max_a = 0;
  long long ans = 0;
  for (int i = 0; i < n; i++) {
    long long ai, bi;
    cin >> ai >> bi;
    b[i] = bi;
    max_a = max(max_a, ai);
  }
  sort(b, b + n);
  for (int i = n - 1; i >= 0; i--) {
    if (b[i] >= max_a) {
      h -= b[i];
      ans++;
      if (h <= 0) break;
    }
  }
  if (h > 0) {
    if (h % max_a == 0) {
      ans += h / max_a;
    } else {
      ans += h / max_a + 1;
    }
  }
  cout << ans << endl;
}
