typedef long long ll; typedef long double ld; #include using namespace std; #define int long long // modint template struct Fp { // inner value long long val; // constructor constexpr Fp() noexcept : val(0) { } constexpr Fp(long long v) noexcept : val(v % MOD) { if (val < 0) val += MOD; } constexpr long long get() const noexcept { return val; } constexpr int get_mod() const noexcept { return MOD; } // arithmetic operators constexpr Fp operator - () const noexcept { return val ? MOD - val : 0; } constexpr Fp operator + (const Fp &r) const noexcept { return Fp(*this) += r; } constexpr Fp operator - (const Fp &r) const noexcept { return Fp(*this) -= r; } constexpr Fp operator * (const Fp &r) const noexcept { return Fp(*this) *= r; } constexpr Fp operator / (const Fp &r) const noexcept { return Fp(*this) /= r; } constexpr Fp& operator += (const Fp &r) noexcept { val += r.val; if (val >= MOD) val -= MOD; return *this; } constexpr Fp& operator -= (const Fp &r) noexcept { val -= r.val; if (val < 0) val += MOD; return *this; } constexpr Fp& operator *= (const Fp &r) noexcept { val = val * r.val % MOD; return *this; } constexpr Fp& operator /= (const Fp &r) noexcept { long long a = r.val, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b, swap(a, b); u -= t * v, swap(u, v); } val = val * u % MOD; if (val < 0) val += MOD; return *this; } constexpr Fp pow(long long n) const noexcept { Fp res(1), mul(*this); while (n > 0) { if (n & 1) res *= mul; mul *= mul; n >>= 1; } return res; } constexpr Fp inv() const noexcept { Fp res(1), div(*this); return res / div; } // other operators constexpr bool operator == (const Fp &r) const noexcept { return this->val == r.val; } constexpr bool operator != (const Fp &r) const noexcept { return this->val != r.val; } friend constexpr istream& operator >> (istream &is, Fp &x) noexcept { is >> x.val; x.val %= MOD; if (x.val < 0) x.val += MOD; return is; } friend constexpr ostream& operator << (ostream &os, const Fp &x) noexcept { return os << x.val; } friend constexpr Fp modpow(const Fp &r, long long n) noexcept { return r.pow(n); } friend constexpr Fp modinv(const Fp &r) noexcept { return r.inv(); } }; // Binomial coefficient template struct BiCoef { vector fact_, inv_, finv_; constexpr BiCoef() {} constexpr BiCoef(int n) noexcept : fact_(n, 1), inv_(n, 1), finv_(n, 1) { init(n); } constexpr void init(int n) noexcept { fact_.assign(n, 1), inv_.assign(n, 1), finv_.assign(n, 1); int MOD = fact_[0].get_mod(); for(int i = 2; i < n; i++){ fact_[i] = fact_[i-1] * i; inv_[i] = -inv_[MOD%i] * (MOD/i); finv_[i] = finv_[i-1] * inv_[i]; } } constexpr T com(int n, int k) const noexcept { if (n < k || n < 0 || k < 0) return 0; return fact_[n] * finv_[k] * finv_[n-k]; } constexpr T fact(int n) const noexcept { if (n < 0) return 0; return fact_[n]; } constexpr T inv(int n) const noexcept { if (n < 0) return 0; return inv_[n]; } constexpr T finv(int n) const noexcept { if (n < 0) return 0; return finv_[n]; } }; signed main(){ ll n,k; std::cin >> n>>k; vector a(n); for (int i = 0; i < n; i++) { std::cin >> a[i]; } sort(a.rbegin(),a.rend()); ll ans = 0; for (int i = 1; i < (1ll<