#include<bits/stdc++.h>
#define ll long long
#define INF 214748364719260817ll
#define MAXN 2147483647ll
using namespace std;
ll n,m;
struct graph
{
	ll head[100005],cnt;
	struct ed
	{
		ll v,next,w;
	}edge[200005];
	void add(ll u,ll v,ll w)
	{
		edge[++cnt].v=v;edge[cnt].next=head[u];head[u]=cnt;edge[cnt].w=w;
		edge[++cnt].v=u;edge[cnt].next=head[v];head[v]=cnt;edge[cnt].w=w;
	}
	ll f[200005][20],tot,lg[200005],dfn[200005],dep[200005],dis[200005];
	ll from[200005][20];
	void clear()
	{
		for(ll i=1;i<=n;++i)head[i]=0;cnt=tot=0;
	}
	void dfs(ll id,ll fa)
	{
		dep[id]=dep[fa]+1;
		f[dfn[id]=++tot][0]=f[dfn[fa]][0]+1;
		from[dfn[id]][0]=id;
		for(ll i=head[id];i;i=edge[i].next)
		{
			ll v=edge[i].v,w=edge[i].w;
			if(v==fa)continue;
			dis[v]=dis[id]+w;
			dfs(v,id);
			f[++tot][0]=dep[id];from[tot][0]=id;
		}
	}
	ll get_lca(ll u,ll v)
	{
		if(dfn[u]>dfn[v])swap(u,v);
		ll use=lg[dfn[v]-dfn[u]+1];
		ll r1=from[dfn[u]][use],r2=from[dfn[v]-(1<<use)+1][use];
		return dep[r1]<dep[r2]?r1:r2;
	}
	void init()
	{
		ll u,v,w;
		for(ll i=1;i<n;++i)cin>>u>>v>>w,add(u,v,w);
		for(ll i=2;i<=2*n-1;++i)lg[i]=lg[i>>1]+1;
		dfs(1,0);
		for(ll i=tot;i>0;--i)
			for(ll j=1;(i+(1<<j)-1)<=tot;++j)
			{
				f[i][j]=f[i][j-1];from[i][j]=from[i][j-1];
				if(f[i][j]>f[i+(1<<(j-1))][j-1])
				f[i][j]=f[i+(1<<(j-1))][j-1],from[i][j]=from[i+(1<<(j-1))][j-1];
			}
	}
	ll get_dis(ll u,ll v)
	{
		return dis[u]+dis[v]-2*dis[get_lca(u,v)];
	}
}g[2];
ll t;
int main()
{
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	random_device my;
	mt19937 rd(my());
	g[0].clear();
	g[1].clear();
	cin>>n>>m;
	g[0].init();
	g[1].init();
	set<ll>p;
	for(ll i=1;i<=36000;++i)
	{
		ll u=rd()%n+1,v=rd()%n+1;
		ll maxn=-1,uid=0;
		for(ll j=1;j<=n;++j)
		{
			ll val=g[0].get_dis(u,j)+g[1].get_dis(v,j);
			if(val>maxn)maxn=val,uid=j;
		}
		p.insert(uid);
	}
	while(m--)
	{
		ll u,v;
		cin>>u>>v;
		ll maxn=-1;
		for(auto it:p)
		{
			ll val=g[0].get_dis(u,it)+g[1].get_dis(v,it);
			maxn=max(maxn,val);
		}
		cout<<maxn<<'\n';
	}
	
}