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