#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
void fast();
int main() {
  fast();
  long long n, h, sum = 0, mx, res = 0;
  cin >> n >> h;
  vector<pair<int, int>> a(n);
  vector<long long> v(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i].first >> a[i].second;
    sum += a[i].second;
    v[i] = a[i].second;
  }
  sort(a.begin(), a.end());
  sort(v.rbegin(), v.rend());
  if (h <= sum) {
    for (int i = 0; i < n && h > 0; i++) h -= v[i], res++;
  } else {
    for (int i = 0; i < n - 1; i++)
      if (a[i].second >= a[n - 1].first) res++, h -= a[i].second;
    long long x = h - a[n - 1].second;
    res += x / a[n - 1].first;
    if (x % a[n - 1].first != 0) res++;
    res++;
  }
  cout << res;
}
void fast() {
  std::ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
}
