#include <bits/stdc++.h>
const int MAX_N = 100000;
int main() {
  int N;
  long long H, a[MAX_N], b[MAX_N];
  std::cin >> N >> H;
  for (int i = 0; i < N; ++i) {
    std::cin >> a[i] >> b[i];
  }
  std::sort(a, a + N, std::greater<long long>());
  std::sort(b, b + N, std::greater<long long>());
  long long max_a = a[0], ans = 0;
  for (int i = 0; i < N; ++i) {
    if (H > 0 and b[i] > max_a) {
      H -= b[i];
      ++ans;
    } else
      break;
  }
  ans += H / max_a;
  if (H % max_a > 0) ++ans;
  std::cout << ans << std::endl;
}
