#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<pair<long long, long long>> v;
  for (int i = 0; i < (int)(n); i++) {
    long long a, b;
    cin >> a >> b;
    v.push_back(make_pair(b, a));
  }
  sort(v.rbegin(), v.rend());
  vector<long long> aa(n, 0);
  aa[n - 1] = v[n - 1].second;
  for (int i = n - 2; i >= 0; i--) {
    aa[i] = max(aa[i + 1], v[i].second);
  }
  long long ans = 1LL << 60;
  for (int i = 0; i < n; i++) {
    long long a = aa[i];
    long long b = v[i].first;
    long long tmp = (h - b + a - 1) / a + i + 1;
    ans = min(ans, tmp);
    h -= b;
  }
  cout << ans << endl;
  return 0;
}
