#include <bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
constexpr int INF = 2000000000;
constexpr int HINF = INF / 2;
constexpr double DINF = 100000000000000000.0;
constexpr long long LINF = 9223372036854775807;
constexpr long long HLINF = 4500000000000000000;
constexpr long long MMOD = 500000004;
const double PI = acos(-1);
int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
int n, h;
vector<pair<int, int>> v;
int main() {
  cin >> n >> h;
  LL ans = 0;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    v.emplace_back(make_pair(a, 1));
    v.emplace_back(make_pair(b, 2));
  }
  sort((v).begin(), (v).end());
  reverse((v).begin(), (v).end());
  for (int i = 0; i < v.size(); i++) {
    if (v[i].second == 2) {
      ans++;
      h -= v[i].first;
    } else {
      if (h % v[i].second == 0) {
        ans += h / v[i].first;
      } else {
        ans += h / v[i].first + 1;
      }
      cout << ans << endl;
      return 0;
    }
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
}
