#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  return b ? gcd(b, a % b) : a;
}
long long int lcm(long long int a, long long int b) {
  return a / gcd(a, b) * b;
}
bool compare_by_b(pair<int, int> a, pair<int, int> b) {
  if (a.first != b.first) {
    return a.first < b.first;
  } else {
    return a.second > b.second;
  }
}
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
  for (int i = 0; i < (int)v.size(); ++i) {
    os << v[i];
    if (i != (int)v.size() - 1) os << " ";
  }
  return os;
}
int main() {
  long long int N, H;
  cin >> N >> H;
  vector<long long int> a(N);
  vector<long long int> b(N);
  for (long long int i = 0; i < (long long int)(N); i++) {
    cin >> a[i] >> b[i];
  }
  long long int ma = *max_element((a).begin(), (a).end());
  long long int cnt = 0;
  sort((b).begin(), (b).end(), greater<long long int>());
  for (long long int i = 0; i < (long long int)(N); i++) {
    if (b[i] > ma) {
      H -= b[i];
      cnt++;
      if (H <= 0) {
        cout << cnt << endl;
        return 0;
      }
    } else {
      break;
    }
  }
  cnt += H / ma;
  cout << cnt << endl;
  return 0;
}
