#include using namespace std; #define REP(i,n) for(int i=0; i<(int)(n); i++) #define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++) #define ALL(x) (x).begin(), (x).end() const double PI = acos(-1); const long long MOD = 1e9 + 7; typedef vector vec; typedef vector matrix; matrix eye(int n) { matrix mat(n, vec(n)); for (int i = 0; i < n; i++) { mat[i][i] = 1; } return mat; } matrix zeros(int r, int c) { return matrix(r, vec(c)); } matrix zeros(int n) { return zeros(n, n); } matrix add(const matrix &a, const matrix &b) { matrix c = zeros(a.size(), a[0].size()); for (int i = 0; i < c.size(); i++) { for (int j = 0; j < c[0].size(); j++) { c[i][j] = a[i][j] + b[i][j]; } } return c; } matrix mul(const matrix &a, const matrix &b) { matrix c = zeros(a.size(), b[0].size()); for (int i = 0; i < a.size(); i++) { for (int k = 0; k < b.size(); k++) { for (int j = 0; j < b[0].size(); j++) { c[i][j] += a[i][k] * b[k][j]; } } } return c; } matrix modmul(const matrix &a, const matrix &b, long long mod) { matrix c = zeros(a.size(), b[0].size()); for (int i = 0; i < a.size(); i++) { for (int k = 0; k < b.size(); k++) { for (int j = 0; j < b[0].size(); j++) { c[i][j] = (c[i][j] + a[i][k] * b[k][j]) % mod; } } } return c; } matrix pow(const matrix &a, long long p) { matrix ret = eye(a.size()); matrix x = a; while (p) { if (p & 1) ret = mul(ret, x); x = mul(x, x); p >>= 1; } return ret; } matrix modpow(const matrix &a, long long p, long long mod) { matrix ret = eye(a.size()); matrix x = a; while (p) { if (p & 1) ret = modmul(ret, x, mod); x = modmul(x, x, mod); p >>= 1; } return ret; } long long modpow(long long x, long long p, long long mod) { long long ret = 1; while (p) { if (p & 1) ret = ret * x % mod; x = x * x % mod; p >>= 1; } return ret; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); int n, m; long long k, p, q; cin >> n >> m >> k >> p >> q; matrix a = zeros(2); long long r = p * modpow(q, MOD-2, MOD) % MOD; a[0][0] = a[1][1] = (1 - r + MOD) % MOD; a[0][1] = a[1][0] = r; a = modpow(a, k, MOD); long long ret = 0; REP (i, n) { long long b; cin >> b; if (i < m) { ret += a[1][1] * b; } else { ret += a[1][0] * b; } ret %= MOD; } cout << ret << endl; return 0; }