#include<bits/stdc++.h>
#define rep(i, a, b) for(int i = (a); i < (b); i++) 
#define _for(i, a, b) for(int i = (a); i <= (b); i++) 
using namespace std;

typedef long long ll;
const int N = 500 + 10;
const int mod = 1e9 + 7;
ll dp[N][N], m;
int a[N], n;

ll cal(int i, int j)
{
	if(a[i] < 0 || a[j] > 0) return 0;
	if(!a[i] && !a[j]) return m;
	if(!a[i] || !a[j]) return 1;
	if(a[i] + a[j] == 0) return 1;
	return 0;
}

ll get(int l, int r)
{
	if(l + 1 == r) return cal(l, r);
	return cal(l, r) * dp[l + 1][r - 1] % mod;
}

int main()
{
	int T; scanf("%d", &T);
	while(T--)
	{
		scanf("%d%lld", &n, &m);
		_for(i, 1, n) scanf("%d", &a[i]);

		for(int len = 2; len <= n; len += 2)
			_for(l, 1, n)
			{
				int r = l + len - 1;
				if(r > n) break;

				dp[l][r] = get(l, r);
				_for(k, l + 1, r - 2)
					(dp[l][r] += get(l, k) * dp[k + 1][r] % mod) %= mod;
			}
		printf("%lld\n", dp[1][n]);
	}

	return 0; 
}