#include #include #include using namespace std; const int MAX = 1000010; const int MOD = 1000000007; using LL = long long; class mint { LL val; mint& normalize(LL x) { val = x % MOD; if (val < 0) { val += MOD; } return *this; } static LL inverse(LL a) { LL u = 0, v = 1, m = MOD; while (a != 0) { LL t = m / a; m -= t * a; swap(a, m); u -= t * v; swap(u, v); } assert(m == 1); return u; } public: mint(LL x = 0) { normalize(x); } LL operator()() const { return val; } template explicit operator U() const { return static_cast(val); } mint& operator=(LL x) { return normalize(x); } mint& operator=(const mint& x) { val = x.val; return *this; } mint& operator+=(const mint& x) { return normalize(val + x.val); } mint& operator-=(const mint& x) { return normalize(val - x.val); } mint& operator*=(const mint& x) { return normalize(val * x.val); } mint& operator/=(const mint& x) { return *this *= mint(inverse(x.val)); } mint& operator+=(LL x) { return *this += mint(x); } mint& operator-=(LL x) { return *this -= mint(x); } mint& operator*=(LL x) { return *this *= mint(x); } mint& operator/=(LL x) { return *this /= mint(x); } mint& operator++() { return *this += 1; } mint& operator--() { return *this -= 1; } mint operator++(int) { mint z(*this); ++*this; return z; } mint operator--(int) { mint z(*this); --*this; return z; } friend mint operator+(mint x, const mint& y) { return x += y; } friend mint operator*(mint x, const mint& y) { return x *= y; } friend mint operator-(mint x, const mint& y) { return x -= y; } friend mint operator/(mint x, const mint& y) { return x /= y; } friend mint operator+(mint x, LL y) { return x += y; } friend mint operator*(mint x, LL y) { return x *= y; } friend mint operator-(mint x, LL y) { return x -= y; } friend mint operator/(mint x, LL y) { return x /= y; } friend mint operator+(LL x, mint y) { return y += x; } friend mint operator*(LL x, mint y) { return y *= x; } friend mint operator-(LL x, const mint& y) { mint z(x); return z -= y; } friend mint operator/(LL x, const mint& y) { mint z(x); return z /= y; } bool operator <(const mint& x) const { return val < x.val; } bool operator==(const mint& x) const { return val == x.val; } bool operator >(const mint& x) const { return val > x.val; } bool operator!=(const mint& x) const { return val != x.val; } bool operator<=(const mint& x) const { return val <= x.val; } bool operator>=(const mint& x) const { return val >= x.val; } bool operator <(LL x) const { return val < x; } bool operator==(LL x) const { return val == x; } bool operator >(LL x) const { return val > x; } bool operator!=(LL x) const { return val != x; } bool operator<=(LL x) const { return val <= x; } bool operator>=(LL x) const { return val >= x; } }; class factorial : vector { void lazy_eval(int n) { for (LL p = size(); n >= p; ++p) { push_back(back() * p); } } public: factorial() { push_back(1); } mint choose(LL n, LL k) { if (n < 0 || k < 0 || n < k) { return 0; } if (k == 0 || k == n) { return 1; } if (n >= MOD && n <= k + MOD - 1) { return 0; } lazy_eval(n); return at(n) / (at(k) * at(n - k)); } mint operator[](LL n) { lazy_eval(n); return at(n); } }; factorial F; vector> divisors(MAX); vector mu(MAX); void build_mu() { vector B(MAX); vector primes; mu[1] = 1LL; for (LL i = 2; i < MAX; i++) { if (!B[i]) { primes.push_back(i); mu[i] = -1; } for (auto& p : primes) { LL k = (LL)i * p; if (k > MAX) { break; } B[k] = 1; if (i % p != 0) { mu[k] = -mu[i]; } else { mu[k] = 0; break; } } } } LL solve() { int N, K, D; cin >> N >> K >> D; vector H(N), freq(MAX); for (int i = 0; i < N; i++) { cin >> H[i]; for (LL d : divisors[H[i]]) { freq[d]++; } } mint ans = 0; for (LL d : divisors[D]) { for (LL j = 0; j < MAX; j++) { LL i = (LL)d * j; if (i > MAX) { break; } ans += F.choose(freq[i], K) * mu[j]; } } return (LL)(ans * F[K]); } int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); for (int i = 1; i < MAX; i++) { for (int j = i; j < MAX; j += i) { divisors[j].push_back(i); } } build_mu(); int T; cin >> T; for (int t = 1; t <= T; t++) { cout << "Case #" << t << ": " << solve() << endl; } return 0; }