#include <bits/stdc++.h>
using namespace std;
int B[100001] = {};
int main() {
  int N, H;
  cin >> N >> H;
  int maxA = 0;
  for (int i = 0; i < N; ++i) {
    int a, b;
    cin >> a >> b;
    maxA = max(a, maxA);
    B[i] = b;
  }
  sort(B, B + N, greater<int>());
  int ans = 0;
  for (int i = 0; i < N; ++i) {
    if (B[i] < maxA) break;
    H -= B[i];
    ++ans;
    if (H <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
  ans += H / maxA;
  if (H % maxA != 0) ++ans;
  cout << ans << endl;
  return 0;
}
