#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  int N;
  ll H;
  cin >> N >> H;
  int a[N + 3], b[N + 3];
  for (int i = 0; i < N; ++i) scanf("%d %d", &a[i], &b[i]);
  sort(a, a + N, [](int &x, int &y) { return x > y; });
  sort(b, b + N, [](int &x, int &y) { return x > y; });
  ll cnt = 0;
  ll am = a[0];
  for (cnt = 0; cnt < (ll)N; ++cnt) {
    if (H < 0) {
      cout << cnt << endl;
      return 0;
    }
    if (b[cnt] < am) break;
    H -= b[cnt];
  }
  if (H >= 0) cnt += (H % am != 0) ? H / am + 1 : H / am;
  cout << cnt << endl;
  return 0;
}
