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