#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll MOD = 1000000007;
constexpr ll INF = 1ll << 60;
int main(int argc, char **argv) {
  ll N, H;
  cin >> N >> H;
  vector<ll> A(N), B(N);
  for (ll i = 0; i < N; ++i) cin >> A[i] >> B[i];
  sort(B.begin(), B.end(), greater<ll>());
  ll amax = *max_element(A.begin(), A.end());
  ll res{0};
  for (ll i = 0; i < N && H > 0; ++i) {
    if (B[i] > amax) {
      H -= B[i];
      ++res;
    } else
      break;
  }
  res += H / amax;
  std::cout << res << std::endl;
}
