#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  long long maks = 0, b[n];
  vector<long long> v;
  for (int i = 0; i < n; i++) {
    long long a;
    cin >> a >> b[i];
    maks = max(maks, a);
  }
  long long sum = 0;
  for (auto &e : b) {
    if (e > maks) {
      v.push_back(e);
      sum += e;
    }
  }
  long long r = 0;
  if (sum > h) {
    r = 0;
    sort(b, b + n);
    sum = 0;
    for (auto &e : b) {
      sum += e;
      r++;
      if (sum >= h) {
        cout << r;
        return 0;
      }
    }
  } else {
    r = 0;
    r += v.size();
    h -= sum;
    if (h % maks) {
      r += h / maks + 1;
    } else
      r += h / maks;
  }
  cout << r;
  return 0;
}
