#include <bits/stdc++.h>
using namespace std;
const long long INF = 1LL << 60;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long n, h;
  cin >> n >> h;
  vector<long long> A(n);
  vector<long long> B(n);
  for (long long i = 0; i < n; i++) {
    cin >> A[i] >> B[i];
  }
  sort(A.begin(), A.end(), greater<long long>());
  sort(B.begin(), B.end(), greater<long long>());
  long long cnt = 0;
  for (long long i = 0; i < n; i++) {
    if (A[0] <= B[i]) {
      h -= B[i];
      cnt++;
      if (h < 0) break;
    } else {
      break;
    }
  }
  if (h > 0) cnt += (h + (A[0] - 1)) / A[0];
  cout << cnt << endl;
}
