#include using namespace std; #define rep(i, n) for(int(i) = 0; (i) < (n); (i)++) #define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++) #define All(v) (v).begin(), (v).end() #define pb push_back #define MP(a, b) make_pair((a), (b)) template vector make_vec(size_t a, T val) { return vector(a, val); } template auto make_vec(size_t a, Ts... ts) { return vector(a, make_vec(ts...)); } using ll = long long; using pii = pair; using pll = pair; using Graph = vector>; template struct edge { int to; T cost; edge(int t, T c) : to(t), cost(c) {} }; template using WGraph = vector>>; const int INF = 1 << 30; const ll LINF = 1LL << 60; const int MOD = 1e9 + 7; template class ModInt { using u64 = uint_fast64_t; public: u64 val; ModInt(const u64 x = 0) : val((x + MOD) % MOD) {} constexpr u64 &value() { return val; } constexpr ModInt operator-() { return val ? MOD - val : 0; } constexpr ModInt operator+(const ModInt &rhs) const { return ModInt(*this) += rhs; } constexpr ModInt operator-(const ModInt &rhs) const { return ModInt(*this) -= rhs; } constexpr ModInt operator*(const ModInt &rhs) const { return ModInt(*this) *= rhs; } constexpr ModInt operator/(const ModInt &rhs) const { return ModInt(*this) /= rhs; } constexpr ModInt &operator+=(const ModInt &rhs) { val += rhs.val; if(val >= MOD) { val -= MOD; } return *this; } constexpr ModInt &operator-=(const ModInt &rhs) { if(val < rhs.val) { val += MOD; } val -= rhs.val; return *this; } constexpr ModInt &operator*=(const ModInt &rhs) { val = val * rhs.val % MOD; return *this; } constexpr ModInt &operator/=(const ModInt &rhs) { *this *= rhs.inv(); return *this; } constexpr bool operator==(const ModInt &rhs) { return this->val == rhs.val; } constexpr bool operator!=(const ModInt &rhs) { return this->val != rhs.val; } friend constexpr ostream &operator<<(ostream &os, const ModInt &x) { return os << x.val; } friend constexpr istream &operator>>(istream &is, ModInt &x) { return is >> x.val; } constexpr ModInt inv() const { return ModInt(*this).pow(MOD - 2); } constexpr ModInt pow(ll e) const { u64 x = 1, p = val; while(e > 0) { if(e % 2 == 0) { p = (p * p) % MOD; e /= 2; } else { x = (x * p) % MOD; e--; } } return ModInt(x); } }; using mint = ModInt; #include // 参考:https://ei1333.github.io/luzhiled/snippets/math/matrix.html // (掛け算と累乗)https://yukicoder.me/submissions/523126 // 他は知らん template struct Matrix { vector> A; Matrix() {} Matrix(size_t n, size_t m) : A(n, vector(m, 0)) {} Matrix(size_t n) : A(n, vector(n, 0)) {} size_t height() const { return A.size(); } size_t width() const { return A[0].size(); } inline vector &operator[](int k) { return A.at(k); } inline const vector &operator[](int k) const { return A.at(k); } static Matrix I(size_t n) { Matrix mat(n); for(int i = 0; i < n; i++) mat[i][i] = 1; return mat; } Matrix &operator+=(const Matrix &B) { size_t h = height(), w = width(); assert(h == B.height() && w == B.width); for(int i = 0; i < h; i++) { for(int j = 0; j < w; j++) { (*this)[i][j] += B[i][j]; } } return *this; } Matrix &operator-=(const Matrix &B) { size_t h = height(), w = width(); assert(h == B.height() && w == B.width); for(int i = 0; i < h; i++) { for(int j = 0; j < w; j++) { (*this)[i][j] -= B[i][j]; } } return *this; } Matrix &operator*=(const Matrix &B) { size_t h = height(), w = B.width(), p = width(); assert(p == B.height()); vector> C(h, vector(w, 0)); for(int i = 0; i < h; i++) { for(int j = 0; j < w; j++) { for(int k = 0; k < p; k++) { C[i][j] += (*this)[i][k] * B[k][j]; } } } A.swap(C); return *this; } Matrix &operator^=(ll k) { Matrix B = Matrix::I(height()); while(k > 0) { if(k & 1) B *= *this; *this *= *this; k >>= 1LL; } A.swap(B.A); return *this; } Matrix operator+(const Matrix &B) const { return (Matrix(*this) += B); } Matrix operator-(const Matrix &B) const { return (Matrix(*this) -= B); } Matrix operator*(const Matrix &B) const { return (Matrix(*this) *= B); } Matrix operator^(const ll k) const { return (Matrix(*this) ^= k); } friend ostream &operator<<(ostream &os, const Matrix &p) { size_t h = p.height(), w = p.width(); for(int i = 0; i < h; i++) { os << "["; for(int j = 0; j < w; j++) { os << p[i][j] << (j + 1 == w ? "]\n" : ","); } } return os; } }; int main() { ll N, M, K, p, q; cin >> N >> M >> K >> p >> q; vector B(N); rep(i, N) cin >> B[i]; Matrix mat(2, 2), vec(2, 1); mint r = mint(p) / q; vec[0][0] = 1; vec[1][0] = 0; mat[0][0] = -r + 1; mat[0][1] = r; mat[1][0] = r; mat[1][1] = -r + 1; auto P = (mat ^ (K)) * vec; mint res = 0; rep(i, N) { if(i < M) { res += P[0][0] * B[i]; } else { res += P[1][0] * B[i]; } } cout << res << endl; }