#include <bits/stdc++.h>
using namespace std;
const long long LINF = 1e18;
const int INF = 1e9;
int main() {
  int N, H;
  cin >> N >> H;
  int a[N], b[N];
  for (int i = 0; i < (int)(N); i++) cin >> a[i] >> b[i];
  sort(a, a + N);
  sort(b, b + N);
  int cnt = 0;
  for (int i = 0; i < (int)(N); i++) {
    if (a[N - 1] < b[i]) cnt++;
  }
  int ans = 0;
  do {
    H -= b[N - cnt];
    cnt--;
    ans++;
  } while (H > 0 && cnt > 0);
  if (H <= 0) {
    cout << ans << endl;
    return 0;
  } else {
    int c = H / a[N - 1];
    if (H % a[N - 1] == 0)
      ans += c;
    else
      ans += (c + 1);
  }
  cout << ans << endl;
  return 0;
}
