#include <map>
#include <set>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 110;
const int M = 10010;
const int inf = 0x3f3f3f3f;

struct node
{
	int weight;
	int next;
	int to;
}edge[M << 1];

struct node2
{
	int w;
	int c;
}num[N];

int tot, n, m;
int head[N];
int dis[N];
bool vis[N];
int dp[M * 10];

void addedge(int from, int to, int weight)
{
	edge[tot].weight = weight;
	edge[tot].next = head[from];
	edge[tot].to = to;
	head[from] = tot++;
}

void spfa(int v0)
{
	dis[v0] = 0;
	queue <int> qu;
	while (!qu.empty())
	{
		qu.pop();
	}
	qu.push(v0);
	while (!qu.empty())
	{
		int u = qu.front();
		qu.pop();
		for (int i = head[u]; ~i; i = edge[i].next)
		{
			int v = edge[i].to;
			if (dis[v] > dis[u] + edge[i].weight)
			{
				dis[v] = dis[u] + edge[i].weight;
				qu.push(v);
			}
		}
	}
}

int main()
{
	int t, u, v, w, ret, Vol;
	bool flag;
	scanf("%d", &t);
	while (t--)
	{
		memset (dis, inf, sizeof(dis));
		memset (head, -1, sizeof(head));
		memset (dp, 0, sizeof(dp));
		memset (vis, 0, sizeof(vis));
		tot = 0;
		scanf("%d%d", &n, &m);
		for (int i = 0; i < m; ++i)
		{
			scanf("%d%d%d", &u, &v, &w);
			addedge(u, v, w);
			addedge(v, u, w);
		}
		spfa(0);
		ret = Vol = 0;
		flag = true;
		for (int i = 1; i <= n; ++i)
		{
			scanf("%d", &num[i].w);
			ret += num[i].w;
			if (dis[i] != inf)
			{
				num[i].c = dis[i];
				Vol += num[i].c;
				vis[i] = 1;
			}
		}
		int ans = inf;
		// printf("%d\n", ret);
		ret = ret / 2 + 1;
		for (int i = 1; i <= n; ++i)
		{
			if (!vis[i])
			{
				continue;
			}
			for (int j = Vol; j >= num[i].c; --j)
			{
				dp[j] = max(dp[j], dp[j - num[i].c] + num[i].w);
				if (dp[j] >= ret)
				{
					ans = min(ans, j);
				}
			}
		}
		if (ans == inf)
		{
			printf("impossible\n");
		}
		else
		{
			printf("%d\n", ans);
		}
	}
	return 0;
}