#include<bits/stdc++.h>
using namespace std;

const long long MaxN = 1e5 + 5;
const long long LOG = 20;

long long n,q;
long long par[MaxN][LOG];
long long mx[MaxN][LOG];
long long d[MaxN];

vector<pair<long long,long long>> vt[MaxN];
pair<long long,long long> pr[MaxN];

void dfs(long long u)
{
    for(auto x : vt[u])
    {
        long long v = x.first;
        long long w = x.second;

        if(v == par[u][0])
            continue;

        par[v][0] = u;
        mx[v][0] = w;
        d[v] = d[u] + 1;

        dfs(v);
    }
}

void build()
{
    for(long long j = 1; j < LOG; j++)
    {
        for(long long i = 1; i <= n; i++)
        {
            par[i][j] = par[par[i][j-1]][j-1];

            mx[i][j] = max(mx[i][j-1],
                           mx[par[i][j-1]][j-1]);
        }
    }
}

long long get_max(long long u, long long anc)
{
    long long ans = 0;

    long long diff = d[u] - d[anc];

    for(long long i = LOG-1; i >= 0; i--)
    {
        if((diff >> i) & 1)
        {
            ans = max(ans, mx[u][i]);
            u = par[u][i];
        }
    }

    return ans;
}

long long lca(long long u, long long v)
{
    if(d[u] < d[v])
        swap(u,v);

    for(long long i = LOG-1; i >= 0; i--)
    {
        if(d[par[u][i]] >= d[v])
            u = par[u][i];
    }

    if(u == v)
        return u;

    for(long long i = LOG-1; i >= 0; i--)
    {
        if(par[u][i] != par[v][i])
        {
            u = par[u][i];
            v = par[v][i];
        }
    }

    return par[u][0];
}

void input()
{
    cin >> n >> q;

    for(long long i = 1; i < n; i++)
    {
        long long u,v,w;
        cin >> u >> v >> w;

        vt[u].push_back({v,w});
        vt[v].push_back({u,w});
    }

    for(long long i = 1; i <= q; i++)
    {
        cin >> pr[i].first >> pr[i].second;
    }
}

void solve()
{
    d[0] = -1;

    dfs(1);
    build();

    for(long long i = 1; i <= q; i++)
    {
        long long u = pr[i].first;
        long long v = pr[i].second;

        long long l = lca(u,v);

        long long ans1 = get_max(u,l);
        long long ans2 = get_max(v,l);

        cout << max(ans1,ans2) << '\n';
    }
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    input();
    solve();
}