#include <bits/stdc++.h>
using ll = long long;
using namespace std;
int main() {
  long n, h;
  vector<long> a, b;
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    long x, y;
    cin >> x >> y;
    a.push_back(x);
    b.push_back(y);
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  long amax = a[0];
  int cnt = 0;
  while (cnt < b.size() && b[cnt] > amax && h > 0) {
    h -= b[cnt];
    cnt++;
  }
  cnt += ceil((double)h / (double)amax);
  cout << cnt << endl;
  return 0;
}
