#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define per(i,a,b) for(int i=a;i>=b;--i)
#define forr(i,a) for(auto i:a)
#define rall(a) rbegin(a),rend(a)
#define all(a) begin(a),end(a)
#define pb emplace_back
using namespace std;
struct read
{
    static const int M = 1 << 23;
    char buf[M], *S = buf, *P = buf, c, l;
    inline char gc() { return (S == P && (P = (S = buf) + fread(buf, 1, M, stdin), S == P) ? EOF : *S++); }
    template<class T> read &operator>>(T &x)
    {
        for (c = 0;!isdigit(c);c = gc()) l = c;
        for (x = 0;isdigit(c);c = gc()) x = x * 10 + (c & 15);
        return x = (l ^ 45) ? x : -x, *this;
    }
}Cin;

constexpr int mod = 1e9 + 7;
template<class T> inline T Norm(const T &v) { return (v % mod + mod) % mod; }
template<class T> constexpr T ksm(T a, int b, const int &p = mod, T c = 1)
{
    for (a %= p;b;(a *= a) %= p, b /= 2) if (b & 1) (c *= a) %= p;
    return c;
}
struct Z
{
    using F = long long; F v;
    Z(long long _x = 0) : v(Norm(_x)) {}
    Z operator-() const { return Z(Norm(mod - v)); }
    Z inv() const { return ksm(*this, mod - 2, mod); }
    Z &operator*=(const Z &R) { return v = v * R.v % mod, *this; }
    Z &operator+=(const Z &R) { return v = Norm(v + R.v), *this; }
    Z &operator-=(const Z &R) { return v = Norm(v - R.v), *this; }
    Z &operator/=(const Z &R) { return *this *= R.inv(); }
    Z &operator%=(const F &R) { return v %= R, *this; }
    friend Z operator*(Z L, const Z &R) { return L *= R; }
    friend Z operator+(Z L, const Z &R) { return L += R; }
    friend Z operator-(Z L, const Z &R) { return L -= R; }
    friend Z operator/(Z L, const Z &R) { return L /= R; }
    friend Z operator%(Z L, const F &R) { return L %= R; }
    auto operator<=>(const Z &) const = default;
    friend auto &operator>>(istream &i, Z &z) { return i >> z.v; }
    friend auto &operator<<(ostream &o, const Z &z) { return o << z.v; }
};

constexpr int N = 510;
int a[N], ndp[N][N]; Z f[N][N];
void solve()
{
    int n, m; Cin >> n >> m;
    rep(i, 1, n) Cin >> a[i];
    if (n & 1) return void(cout << "0\n");
    for (int len = 2;len <= n;len += 2)
        for (int i = 1, j = len;j <= n;++i, ++j)
        {
            if (!a[i] || !a[j])
            {
                if (!a[i] && !a[j]) f[i][j] = f[i + 1][j - 1] * m;
                else if (a[i]) f[i][j] = f[i + 1][j - 1] * (a[i] > 0);
                else f[i][j] = f[i + 1][j - 1] * (a[j] < 0);
            }
            else f[i][j] = f[i + 1][j - 1] * (a[i] > 0 && a[j] < 9 && a[i] + a[j] == 0);
            ndp[i][j] = f[i][j].v;
            for (int k = i;k <= j - 1;++k) f[i][j] += f[i][k] * ndp[k + 1][j];
        }
    cout << f[1][n] << '\n';
}
signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    rep(i, 1, 505) f[i][i - 1] = ndp[i][i - 1] = 1;
    int _;for (Cin >> _; _--; ) solve();
    return 0;
}