#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
const long long INF = 1LL << 60;
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
using Graph = vector<vector<int>>;
int main() {
  long long N, H;
  cin >> N >> H;
  vector<long long> A, B;
  A = B = vector<long long>(N, 0);
  for (int i = 0; i < (N); i++) {
    cin >> A[i] >> B[i];
  }
  long long max_a = 0;
  for (int i = 0; i < (N); i++) {
    max_a = max(max_a, A[i]);
  }
  sort(B.begin(), B.end(), greater<long long>());
  long long ans = INF;
  for (int i = 0; i < (N); i++) {
    H -= B[i];
    long long a_count = (H + (max_a - 1)) / max_a;
    ans = min(ans, a_count + i + 1);
  }
  cout << ans << endl;
}
