#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>
#include<math.h>
#include<set>
#include <random>
#include<numeric>
#include<string>
#include<string.h>
#include<iterator>
#include<fstream>
#include<map>
#include<unordered_map>
#include<stack>
#include<list>
#include<queue>
#include<iomanip>
#include<bitset>
​
//#pragma GCC optimize(2)
//#pragma GCC optimize(3)
​
#define endl '\n'
#define int ll
#define PI acos(-1)
#define INF 0x3f3f3f3f
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll>PII;
const int N = 5e5 + 50, MOD = 998244353;
​
vector<int>tree[N];
int deep[N], fa[N][32], dis[N];
//存储的是边权
unordered_map<int, unordered_map<int, int>>mymap;
​
int lca(int x, int y)
{
    if (deep[x] != deep[y])
    {
        if (deep[x] < deep[y])swap(x, y);
        for (int i = 20; i >= 0; i--)
        {
            if (deep[fa[x][i]] >= deep[y])x = fa[x][i];
        }
    }
    if (x == y)return x;
    for (int i = 20; i >= 0; i--)
    {
        int a = fa[x][i], b = fa[y][i];
        if (a != b)
        {
            x = a, y = b;
        }
    }
    return fa[x][0];
}
​
void dfs(int x, int y)
{
    fa[x][0] = y;
    for (int i = 1; i < 20; i++)
    {
        fa[x][i] = fa[fa[x][i - 1]][i - 1];
    }
    for (auto& i : tree[x])
    {
        if (i == y)continue;
        deep[i] = deep[x] + 1;
        //i点到1的距离就是：父节点到1的距离+父节点到它的距离
        dis[i] = dis[x] + mymap[x][i];
        dfs(i, x);
    }

}
​
void solve()
{
    //因为是多组数据，所以每次要把stl清空
    tree->clear();
    mymap.clear();
    int n, m, x, y, w;
    cin >> n >> m;
    for (int i = 1; i < n; i++)
    {
        cin >> x >> y >> w;
        tree[y].push_back(x);
        tree[x].push_back(y);
        mymap[x][y] = w;
        mymap[y][x] = w;
    }
    //题目没给我们root，我们设1为根
    deep[1] = 1;
    dfs(1, 0);

    while (m--)
    {
        cin >> x >> y;
        int z = lca(x, y);
        cout << dis[x] + dis[y] - dis[z] * 2 << endl;
    }
}
​
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t = 1;
     cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}