//离线查询tarjan算法
#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> PII;
const int N = 1e4 + 10, M = 2 * N + 10;
int n, m;
int h[N], e[M], ne[M], w[M], idx;
int dist[N];
int ans[M];
int st[N];
int p[N];
vector<PII> query[N];//查询 first 是 点 second 是第几次询问；
void add(int a, int b, int c)
{
    e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx ++;
}


int find(int x)
{
    if (p[x] != x) p[x] = find(p[x]);
    return p[x];
}

void dfs(int u, int fa)
{
    for (int i = h[u]; ~i; i = ne[i])
    {
        int j = e[i];
        if (j == fa) continue;
        dist[j] = dist[u] + w[i];
        dfs(j, u);

    }
}

void tarjan(int u)
{
    st[u] = 1;
    for (int i = h[u]; ~i; i = ne[i])
    {
        int j = e[i];
        if (!st[j])
        {
            tarjan(j);
            p[j] = u;
        }
    }

    for (auto item: query[u])
    {
        int y = item.first, id = item.second;
        if (st[y] == 2)
        {
            int t = find(y);
            ans[id] = dist[u] + dist[y] - 2 * dist[t];
        }
    }
    st[u] = 2;
}

int main(void)
{
    cin >> n >> m;

    memset(h, -1, sizeof h);

    for (int i = 0; i < n - 1; i ++)
    {
        int a, b, c;
        cin >> a >> b >> c;
        add(a, b, c), add(b, a, c);
    }

    for (int i = 0; i < m; i ++)
    {
        int a, b;
        cin >> a >> b;
        if (a != b)
        {
            query[a].push_back({b, i});
            query[b].push_back({a, i});
        }
    }
    for (int i = 1; i <= n; i ++)   p[i] = i;

    dfs(1, -1);
    tarjan(1);

    for (int i = 0; i < m; i ++)
        cout << ans[i] << endl;

    return 0;
}