#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H, ans = 0, bsum = 0, bn = 0, sum = 0;
  cin >> N >> H;
  vector<int> a(N), b(N);
  for (int i = 0; i < N; i++) {
    cin >> a.at(i) >> b.at(i);
  }
  sort(a.begin(), a.end(), greater<int>());
  sort(b.begin(), b.end(), greater<int>());
  for (int i = 0; i < N; i++) {
    if (b.at(i) < a.at(0)) break;
    bsum = bsum + b.at(i);
    bn = i + 1;
  }
  if (bsum >= H) {
    ans = bn;
  } else {
    ans = bn;
    sum = bsum;
    while (sum < H) {
      sum = sum + a.at(0);
      ans++;
    }
  }
  cout << ans << endl;
}
