Factory Machines

  #include <bits/stdc++.h>
  using namespace std;

  #define cin(vec) for(auto& i : vec) cin >> i
  #define cin_2d(vec, n, m) for(int i = 0; i < n; i++) for(int j = 0; j < m && cin >> vec[i][j]; j++);
  #define cout(vec) for(auto& i : vec) cout << i << " "; cout << "\n";
  #define cout_2d(vec, n, m) for(int i = 0; i < n; i++, cout << "\n") for(int j = 0; j < m && cout << vec[i][j] << " "; j++);
  #define cout_map(mp) for(auto& [f, s] : mp) cout << f << "  " << s << "\n";
  #define fixed(n) cout << fixed << setprecision(n);
  #define ceil(n, m) (((n) / (m)) + ((n) % (m) ? 1 : 0))
  #define fill(vec, value) memset(vec, value, sizeof(vec));
  #define Num_of_Digits(n) ((int)log10(n)+1)
  #define all(vec) vec.begin(),vec.end()
  #define rall(vec) vec.rbegin(),vec.rend()
  #define sz(x) int(x.size())
  #define fi first
  #define se second
  #define Pair pair < int, int >
  #define ll long long
  #define ull unsigned long long
  #define Mod  1'000'000'007
  #define INF 2'000'000'000
  #define PI acos(-1)

  void Code_Crush(){
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    #ifndef ONLINE_JUDGE
      freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
    #endif
  }
  ll n, x;
  vector < int > machines(2 * 1e5 + 1);
  bool can_achieve(ll seconds){
    ll products = 0;
    for(auto& it : machines){
      products += seconds / it;
      if(products >= x) return true;
    }
    return products >= x;
  }

  ll Binary_Search(){
    ll l = 1, r = 1e18, best = -1;
    while(l <= r){
      ll m = l + (r - l) / 2;
      (can_achieve(m) ? r = m - 1, best = m : l = m + 1);
    }
    return best;
  }

  int main(){
      Code_Crush();
      cin >> n >> x;
      machines.resize(n);
      cin(machines);
      sort(all(machines));
      cout << Binary_Search();
      return 0;
  }