#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<ctime>
#include<queue>
#include<stack>
#include<deque>
#include<map>
#include<unordered_map>
#include<set>
#include<unordered_set>
#include<bitset>
#include<functional>
using namespace std;
//STL库常用(vector, map, set, pair)
#define pii pair<int,int>
#define pdd pair<double,double>
#define F first
#define S second
//常量
#define PI (acos(-1.0))
#define INF 0x3f3f3f3f
//必加
#ifdef TanJI
#include<cassert>
#define dbg(...) do {cerr << #__VA_ARGS__ << " -> "; err(__VA_ARGS__); } while(0)
void err() {cerr << endl;}
template<template<typename...> class T, typename t, typename... A> void err(T<t> a, A... x) {for (auto v: a) cerr << v << ' '; cerr << ", "; err(x...);}
template<typename T, typename... A> void err(T a, A... x) {cerr << a << ' '; err(x...);}
template<typename T> void err(T *a, int len) {for (int i = 0; i < len; i++) cerr << a[i] << ' '; err();}
#else 
#define dbg(...)
#define assert(...)
#endif
typedef unsigned long long ull;
typedef long long ll;
typedef double db;
// 快读快输
template<typename T> inline T read() {T x=0; bool f=0; char c=getchar();while(!isdigit(c)){if(c =='-')f= 1; c=getchar();}while(isdigit(c)){x=(x<<3)+(x<<1)+(c^48);c=getchar();}return f?~x+1:x;}
template<typename T> inline void print(T k){ int num = 0,ch[20]; if(k == 0){ putchar('0'); return ; } (k<0)&&(putchar('-'),k = -k); while(k>0) ch[++num] = k%10, k /= 10; while(num) putchar(ch[num--]+48); }
//图论
const int GRAPHN = 1, GRAPHM = 1;
int h[GRAPHN], e[GRAPHM], ne[GRAPHM], wei[GRAPHM], idx;
void AddEdge(int a, int b) {e[idx] = b, ne[idx] = h[a], h[a] = idx++;}
void AddEdge(int a, int b, int c) {e[idx] = b, ne[idx] = h[a], wei[idx] = c, h[a] = idx++;}
void AddEdge(int h[], int a, int b) {e[idx] = b, ne[idx] = h[a], h[a] = idx++;}
void AddEdge(int h[], int a, int b, int c) {e[idx] = b, ne[idx] = h[a], wei[idx] = c, h[a] = idx++;}
// 数学公式
template<typename T> inline T gcd(T a, T b){ return b==0 ? a : gcd(b,a%b); }
template<typename T> inline T lowbit(T x){ return x&(-x); }
template<typename T> inline bool mishu(T x){ return x>0?(x&(x-1))==0:false; }
template<typename T1,typename T2, typename T3> inline ll q_mul(T1 a,T2 b,T3 p){ ll w = 0; while(b){ if(b&1) w = (w+a)%p; b>>=1; a = (a+a)%p; } return w; }
template<typename T,typename T2> inline ll f_mul(T a,T b,T2 p){ return (a*b - (ll)((long double)a/p*b)*p+p)%p; }
template<typename T1,typename T2, typename T3> inline ll q_pow(T1 a,T2 b,T3 p){ ll w = 1; while(b){ if(b&1) w = (w*a)%p; b>>=1; a = (a*a)%p;} return w; }
template<typename T1,typename T2, typename T3> inline ll s_pow(T1 a,T2 b,T3 p){ ll w = 1; while(b){ if(b&1) w = q_mul(w,a,p); b>>=1; a = q_mul(a,a,p);} return w; }
template<typename T> inline ll ex_gcd(T a, T b, T& x, T& y){ if(b == 0){ x = 1, y = 0; return (ll)a; } ll r = ex_gcd(b,a%b,y,x); y -= a/b*x; return r;/*gcd*/ }
template<typename T1,typename T2> inline ll com(T1 m, T2 n) { int k = 1;ll ans = 1; while(k <= n){ ans=((m-k+1)*ans)/k;k++;} return ans; }
template<typename T> inline bool isprime(T n){ if(n <= 3) return n>1; if(n%6 != 1 && n%6 != 5) return 0; T n_s = floor(sqrt((db)(n))); for(int i = 5; i <= n_s; i += 6){ if(n%i == 0 || n%(i+2) == 0) return 0; } return 1; }
/* ----------------------------------------------------------------------------------------------------------------------------------------------------------------- */

const int MAXN = 510;
const int MOD = 1e9 + 7;

int n, m;
ll dp[MAXN][MAXN], con[MAXN][MAXN];
int a[MAXN];
//con[l][r] = dp[l + 1][r - 1]
//dp[l][r] = sum(con[l][k] * con[k + 1][r]), k=l-1~r-2;


int main() {
#ifdef TanJI
    clock_t c1 = clock();
    freopen("D:\\Cpp\\1.in", "r", stdin);
    freopen("D:\\Cpp\\1.out", "w", stdout);
#endif
//--------------------------------------------
    int T;
    scanf("%d", &T);
    while (T--) {
        scanf("%d%d", &n, &m);
        for (int i = 1; i <= n; i++) 
            scanf("%d", &a[i]);
        if (n % 2) {
            printf("0\n");
            continue;
        }
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                dp[i][j] = con[i][j] = 0;
        for (int i = 1; i <= n + 1; i++) 
            dp[i][i - 1] = 1, con[i][i - 1] = 1;
        for (int i = 2; i <= n; i += 2) {
            for (int l = 1; l + i - 1 <= n; l++) {
                int r = l + i - 1;
                if (a[l] != 0 && a[r] != 0 && a[l] != -a[r]) 
                    con[l][r] = 0;
                else if (a[l] || a[r])
                    con[l][r] = dp[l + 1][r - 1];
                else 
                    con[l][r] = dp[l + 1][r - 1] * m % MOD;
                for (int k = l + 1; k <= r; k += 2) {
                    dp[l][r] = (dp[l][r] + con[l][k] * dp[k + 1][r] % MOD) % MOD;
                }
            }
        }
        printf("%lld\n", dp[1][n]);
    }
//--------------------------------------------    
#ifdef TanJI
    cerr << "Time Used:" << clock() - c1 << "ms" << endl;
#endif
    return 0;
}