#include <bits/stdc++.h>
using namespace std;
int dx[] = {0, 1, 0, -1, 1, 1, -1, -1};
int dy[] = {1, 0, -1, 0, 1, -1, 1, -1};
void fast() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
}
pair<long long, long long> arr[100001];
int main() {
  fast();
  int n;
  long long h;
  cin >> n >> h;
  for (int i = 0; i < n; i++) cin >> arr[i].first >> arr[i].second;
  sort(arr, arr + n,
       [](pair<long long, long long> a, pair<long long, long long> b) {
         if (a.second > b.second)
           return true;
         else if (a.second == b.second && a.first >= b.first)
           return true;
         return false;
       });
  long long mn = LLONG_MAX;
  long long sum = 0, cnt = 0;
  for (int i = 0; i < n; i++) {
    cnt++;
    sum += arr[i].second;
    long long x = max(0LL, h - sum);
    mn = min(mn, cnt + x / arr[i].first + (x % arr[i].first ? 1LL : 0LL));
    mn = min(mn, h / arr[i].first + (h % arr[i].first ? 1LL : 0LL));
  }
  cout << mn << "\n";
}
