Problem p02814 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<int>;
using VL = vector<ll>;
template <class T> using PQ = priority_queue<T, vector<T>, greater<T>>;
#define FOR(i, a, n) for (int(i) = (a); (i) < (n); ++(i))
#define eFOR(i, a, n) for (int(i) = (a); (i) <= (n); ++(i))
#define rFOR(i, a, n) for (int(i) = (n)-1; (i) >= (a); --(i))
#define erFOR(i, a, n) for (int(i) = (n); (i) >= (a); --(i))
#define each(i, a) for (auto &i : a)
#define SORT(i) sort((i).begin(), (i).end())
#define rSORT(i, a) sort((i).begin(), (i).end(), (a))
#define all(i) (i).begin(), (i).end()
#define out(y, x) ((y) < 0 || h <= (y) || (x) < 0 || w <= (x))
#define line cout << "------------------------\n"
#define ENDL(i, n) ((i) == (n)-1 ? "\n" : " ")
#define stop system("pause") // comment out this on AOJ.
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10; // 1e-9?
constexpr ld pi = 3.1415926535897932;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
inline void init() {
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
}
template <class T> inline istream &operator>>(istream &is, vector<T> &v) {
  for (auto &elemnt : v)
    is >> elemnt;
  return is;
}
template <class T, class U>
inline istream &operator>>(istream &is, pair<T, U> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> inline vector<T> vec(size_t a) { return vector<T>(a); }
template <class T> inline vector<T> defvec(T def, size_t a) {
  return vector<T>(a, def);
}
template <class T, class... Ts> inline auto vec(size_t a, Ts... ts) {
  return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...));
}
template <class T, class... Ts> inline auto defvec(T def, size_t a, Ts... ts) {
  return vector<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...));
}

ll gcd(ll a, ll b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }

int main() {
  init();

  int n, m;
  cin >> n >> m;
  VL a(n);
  cin >> a;

  set<int> c;
  FOR(i, 0, n) FOR(j, 0, 40) if (a[i] & (1LL << j)) {
    c.insert(j);
    break;
  }
  if (c.size() != 1) {
    cout << "0\n";
    return 0;
  }

  ll x = 1;
  FOR(i, 0, n) x = max(lcm(x, a[i]), 0LL);
  if (x % 2 == 1) {
    cout << "0\n";
    return 0;
  }

  ll ans = (m + x / 2) / x;
  cout << ans << "\n";
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<int>;
using VL = vector<ll>;
template <class T> using PQ = priority_queue<T, vector<T>, greater<T>>;
#define FOR(i, a, n) for (int(i) = (a); (i) < (n); ++(i))
#define eFOR(i, a, n) for (int(i) = (a); (i) <= (n); ++(i))
#define rFOR(i, a, n) for (int(i) = (n)-1; (i) >= (a); --(i))
#define erFOR(i, a, n) for (int(i) = (n); (i) >= (a); --(i))
#define each(i, a) for (auto &i : a)
#define SORT(i) sort((i).begin(), (i).end())
#define rSORT(i, a) sort((i).begin(), (i).end(), (a))
#define all(i) (i).begin(), (i).end()
#define out(y, x) ((y) < 0 || h <= (y) || (x) < 0 || w <= (x))
#define line cout << "------------------------\n"
#define ENDL(i, n) ((i) == (n)-1 ? "\n" : " ")
#define stop system("pause") // comment out this on AOJ.
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10; // 1e-9?
constexpr ld pi = 3.1415926535897932;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
inline void init() {
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
}
template <class T> inline istream &operator>>(istream &is, vector<T> &v) {
  for (auto &elemnt : v)
    is >> elemnt;
  return is;
}
template <class T, class U>
inline istream &operator>>(istream &is, pair<T, U> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> inline vector<T> vec(size_t a) { return vector<T>(a); }
template <class T> inline vector<T> defvec(T def, size_t a) {
  return vector<T>(a, def);
}
template <class T, class... Ts> inline auto vec(size_t a, Ts... ts) {
  return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...));
}
template <class T, class... Ts> inline auto defvec(T def, size_t a, Ts... ts) {
  return vector<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...));
}

ll gcd(ll a, ll b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }

int main() {
  init();

  int n, m;
  cin >> n >> m;
  VL a(n);
  cin >> a;

  set<int> c;
  FOR(i, 0, n) FOR(j, 0, 40) if (a[i] & (1LL << j)) {
    c.insert(j);
    break;
  }
  if (c.size() != 1) {
    cout << "0\n";
    return 0;
  }

  ll x = 1;
  FOR(i, 0, n) x = lcm(x, a[i]);
  if (x % 2 == 1) {
    cout << "0\n";
    return 0;
  }

  ll ans = (m + x / 2) / x;
  cout << ans << "\n";
}