#include <iostream>
#include <algorithm>
#include <vector>
#include <climits>
using namespace std;
#define int long long
const int MAXN = 1e6 + 5;
const int MOD = 1000000007;
int n, m, k;
int cnt, head[MAXN];
struct Node {
    int to, next, w;
}e[2 * MAXN];
void init() {
    for (int i = 0; i < MAXN; i++) {
        head[i] = -1;
    }
    cnt = 0;
}
void add(int x, int y, int w) {
    e[cnt].to = y;
    e[cnt].next = head[x];
    e[cnt].w = w;
    head[x] = cnt++;
}
int p, mmin, vis[MAXN];
int sz[MAXN], nsz[MAXN];
int dp[MAXN], g[MAXN];
int a[MAXN], b[MAXN];
int xb;
int result = 0;
void DFS1(int x, int fa, int k) {
    //cout << x << ' ' << fa << ' ' << k << endl;
    sz[x] = 1;
    dp[x] = 0;
    vis[x] = k;
    for (int i = head[x]; ~i; i = e[i].next) {
        int v = e[i].to;
        if (v == fa) {
            continue;
        }
        DFS1(v, x, k);
        sz[x] += sz[v];
        dp[x] += dp[v] + e[i].w * sz[v];
    }
}
void DFS2(int x, int fa, int k) {
    if (g[x] < mmin) {
        mmin = g[x];
        p = x;
    }
    for (int i = head[x]; ~i; i = e[i].next) {
        int v = e[i].to;
        if (fa == v) {
            continue;
        }
        g[v] = g[x] + e[i].w * (sz[k] - 2 * sz[v]);
        DFS2(v, x, k);
    }
}
void DFS3(int x, int fa) {
    //cout << x << ' ' << fa << endl;
    nsz[x] = 1;
    for (int i = head[x]; ~i; i = e[i].next) {
        int v = e[i].to;
        if (v == fa) {
            continue;
        }
        DFS3(v, x);
        result = (result + (n - nsz[v]) * nsz[v] * e[i].w) % MOD;
        nsz[x] += nsz[v];
    }
}

bool cmp(int x, int y) {
    return sz[x] > sz[y];
}
main() {
    init();
    cin >> n >> m;
    k = n - m - 1;
    while(m--){
        int x, y, z;
        cin >> x >> y >> z;
        add(x, y, z);
        add(y, x, z);
    }
    for (int i = 1; i <= k; i++) {
        cin >> a[i];
    }
    sort(a + 1, a + k + 1);
    for (int i = 1; i <= n; i++) {
        if (vis[i]) {
            continue;
        }
        DFS1(i, -1, i);
        mmin = INT_MAX;
        g[i] = dp[i];
        DFS2(i, -1, i);
        sz[p] = sz[i];
        b[++xb] = p;
    }
    //cout << "xb:" << xb << endl;
    sort(b + 1, b + xb + 1, cmp);
    for (int i = 2; i <= xb; i++) {
        //cout << b[i] << endl;
        add(b[1], b[i], a[i - 1]);
        add(b[i], b[1], a[i - 1]);
    }
    DFS3(b[1], -1);
    cout << result << endl;
    return 0;
}