#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  int Ai;
  int maxA = 0;
  vector<int> B(N);
  for (int i = 0; i < N; i++) {
    cin >> Ai >> B[i];
    maxA = max(maxA, Ai);
  }
  sort(B.begin(), B.end(), greater<int>());
  int res = numeric_limits<int>::max();
  int sumB = 0;
  for (int i = 0; i <= N; i++) {
    auto c = (H - sumB + maxA - 1) / maxA + i;
    res = min(res, c);
    if (i == N) break;
    sumB += B[i];
  }
  cout << res << endl;
  return 0;
}
