#pragma GCC optimize(2)
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define PII pair<int,int>
#define lson 2*p
#define rson 2*p+1
#define x first
#define y second
//#define endl "\n"
const int N=2e5+10;
const int mod=1e9+7;
int n,m;
int dp[505][505][2];
int a[N];
void solve() {
	cin>>n>>m;
	for(int i=1;i<=n;i++) cin>>a[i];
	if(n&1) {
		cout<<0<<endl;
		return ;
	}
	for(int i=0;i<=n;i++) {
		for(int j=0;j<=n;j++) {
			dp[i][j][0]=dp[i][j][1]=0;
		}
	}
	for(int i=1;i<n;i++) {
		if(a[i]!=0&&a[i+1]!=0) {
			if(a[i]+a[i+1]==0&&a[i]>0) dp[i][i+1][1]=1;
			else dp[i][i+1][1]=0;
		} else if(!a[i]&&!a[i+1]) {
			dp[i][i+1][1]=m;
		} else {
			dp[i][i+1][1]=1;
		}
	}
	for(int len=4;len<=n;len+=2) {
		for(int i=1;i+len-1<=n;i++) {
			int j=i+len-1;
			for(int k=i+1;k<=j-2;k+=2) {
				dp[i][j][0]=(dp[i][j][0]+(dp[i][k][0]+dp[i][k][1])%mod*dp[k+1][j][1]%mod)%mod;
			}
			if(a[i]!=0&&a[j]!=0) {
				if(a[i]+a[j]==0&&a[i]>0) dp[i][j][1]=(dp[i][j][1]+dp[i+1][j-1][0]+dp[i+1][j-1][1])%mod;
			} else if(a[i]==0&&a[j]==0) {
				dp[i][j][1]=(dp[i][j][1]+(dp[i+1][j-1][0]+dp[i+1][j-1][1])*m%mod)%mod;
			} else {
				dp[i][j][1]=(dp[i][j][1]+dp[i+1][j-1][0]+dp[i+1][j-1][1])%mod;
			}
		}
	}
	int ans=(dp[1][n][0]+dp[1][n][1])%mod;
	cout<<ans<<endl;
}
signed main() {
	// ios::sync_with_stdio(false);
	// cin.tie(0);
//	cout.tie(0);
	int T=1;
	cin>>T;
	while(T--) {
		solve();
	}
}