// github.com/Johniel/contests // yukicoder/2253/main.cpp #include #define each(i, c) for (auto& i : c) #define unless(cond) if (!(cond)) // #define endl "\n" using namespace std; template ostream& operator << (ostream& os, pair p) { os << "(" << p.first << "," << p.second << ")"; return os; } template istream& operator >> (istream& is, pair& p) { is >> p.first >> p.second; return is; } template ostream& operator << (ostream& os, vector v) { os << "("; for (auto& i: v) os << i << ","; os << ")"; return os; } template istream& operator >> (istream& is, vector& v) { for (auto& i: v) is >> i; return is; } template ostream& operator << (ostream& os, set s) { os << "#{"; for (auto& i: s) os << i << ","; os << "}"; return os; } template ostream& operator << (ostream& os, map m) { os << "{"; for (auto& i: m) os << i << ","; os << "}"; return os; } template istream& operator >> (istream& is, array& a) { for (auto& i: a) is >> i; return is; } template ostream& operator << (ostream& os, array& a) { os << "[" << N << "]{"; for (auto& i: a) os << i << ","; os << "}"; return os; } template inline T setmax(T& a, T b) { return a = std::max(a, b); } template inline T setmin(T& a, T b) { return a = std::min(a, b); } __attribute__((constructor)) static void ___initio(void) { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.setf(ios_base::fixed); cout.precision(15); return ; } using lli = long long int; using ull = unsigned long long; using str = string; template using vec = vector; constexpr array di({0, 1, -1, 0, 1, -1, 1, -1}); constexpr array dj({1, 0, 0, -1, 1, -1, -1, 1}); constexpr lli mod = 1e9 + 7; // constexpr lli mod = 998244353; int main(int argc, char *argv[]) { int n; lli p; while (cin >> n >> p) { vec a(n); cin >> a; sort(a.begin(), a.end()); lli z = 0; lli w = 1; for (int k = 0; k < 33; ++k) { w *= p; vec b; each (i, a) b.push_back(i % w); map m; each (i, b) { z += m[i]; ++m[i]; } if (a == b) break; } cout << z << endl; } return 0; }