#ifdef LOCAL #include #else #pragma GCC optimize("O3,unroll-loops") #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2") #include #define debug(...) ((void)0) #define postprocess(...) ((void)0) #endif using namespace std; using ll = long long; using ld = long double; void solve([[maybe_unused]] int test) { ll N, P; cin >> N >> P; vector A(N); for (auto&& x : A) { cin >> x; } ll ans = 0; ll MOD = P; while (MOD <= *max_element(A.begin(), A.end())) { map m; for (int i = 0; i < N; i++) { ll rem = A[i] % MOD; ans += m[rem]; m[rem]++; } MOD *= P; } cout << ans << endl; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t = 1; // cin >> t; for (int i = 1; i <= t; i++) { solve(i); } postprocess(); }