#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#define ll long long
using namespace std;
const ll inf=1000000000000000ll;
int read(){
	int x=0;
	char ch=getchar();
	while(ch<'0'||ch>'9')ch=getchar();
	while(ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
	return x;
}
int n,q,a[500005],b[500005];
vector<int> qid[500005];
ll ans[500005];
ll val[100005];
struct qwq{
	int u[200005],v[200005],w[200005],first[100005],nxt[200005];
	int idx,dfn[200005];
	void dfs(int now,int fa){
		dfn[now]=++idx;
		for (int i=first[now];i;i=nxt[i])
			if (v[i]!=fa)dfs(v[i],now);
		return;
	}
	void init(){
		for (int i=1;i<n;i++){
			u[i]=read(),v[i]=read(),w[i]=read();
			nxt[i]=first[u[i]],first[u[i]]=i;
			u[i+n]=v[i],v[i+n]=u[i],w[i+n]=w[i];
			nxt[i+n]=first[u[i+n]],first[u[i+n]]=i+n;
		}
		dfs(1,0);
		return;
	}
}qwq1,qwq2;
namespace T2{
	int u[200005],v[200005],w[200005],first[100005],nxt[200005];
	int idx,ord[200005];
	int log_2[200005];
	ll sum[200005];
	ll st[20][200005];
	void dfs(int now,int f,ll s){
		sum[now]=s;
		++idx;
		ord[now]=idx;
		st[0][idx]=s;
		for (int i=first[now];i;i=nxt[i])
			if (v[i]!=f){
				dfs(v[i],now,s+w[i]);
				++idx;
				st[0][idx]=s;
			}
		return;
	}
	ll dis(int a,int b){
		int l=min(ord[a],ord[b]),r=max(ord[a],ord[b]);
		int w=log_2[r-l+1];
		return val[a]+val[b]+sum[a]+sum[b]-2*min(st[w][l],st[w][r-(1<<w)+1]);
	}
	struct node{
		int a,b;
		ll c;
		node(){
			a=b=-1;
			c=0;
			return;
		}
		node operator +(const node &y)const{
			node ans;
			if (c>=y.c)ans.a=a,ans.b=b,ans.c=c;
			else ans.a=y.a,ans.b=y.b,ans.c=y.c;
			ll d=0;
			d=dis(a,y.a);
			if (d>ans.c)ans.a=a,ans.b=y.a,ans.c=d;
			d=dis(a,y.b);
			if (d>ans.c)ans.a=a,ans.b=y.b,ans.c=d;
			d=dis(b,y.a);
			if (d>ans.c)ans.a=b,ans.b=y.a,ans.c=d;
			d=dis(b,y.b);
			if (d>ans.c)ans.a=b,ans.b=y.b,ans.c=d;
			return ans;
		}
	};
	node tree[262144];
	void pushup(int now){
		tree[now]=tree[now*2]+tree[now*2+1];
		return;
	}
	void build(int now,int nowl,int nowr){
		if (nowl==nowr){
			tree[now].a=tree[now].b=nowl,tree[now].c=0;
			return;
		}
		int mid=(nowl+nowr)/2;
		build(now*2,nowl,mid);
		build(now*2+1,mid+1,nowr);
		pushup(now);
		return;
	}
	int upd_fg;
	void upd(int now,int nowl,int nowr,int pos){
		if (nowl==nowr){
			tree[now].a=tree[now].b=nowl,tree[now].c=0;
			upd_fg=1;
			return;
		}
		int mid=(nowl+nowr)/2;
		if (pos<=mid)upd(now*2,nowl,mid,pos);
		else upd(now*2+1,mid+1,nowr,pos);
		if (upd_fg==1){
			node qwq=tree[now];
			pushup(now);
			if (tree[now].a==qwq.a&&tree[now].b==qwq.b&&tree[now].c==qwq.c)upd_fg=0;
		}
		return;
	}
	void init(){
		qwq2.init();
		for (int i=1;i<n;i++){
			u[i]=qwq2.dfn[qwq2.u[i]],v[i]=qwq2.dfn[qwq2.v[i]],w[i]=qwq2.w[i];
			nxt[i]=first[u[i]],first[u[i]]=i;
			u[i+n]=v[i],v[i+n]=u[i],w[i+n]=w[i];
			nxt[i+n]=first[u[i+n]],first[u[i+n]]=i+n;
		}
		dfs(1,0,0);
		for (int i=2;i<=idx;i++)log_2[i]=log_2[i/2]+1;
		for (int w=1;w<20;w++)
			for (int i=1;i+(1<<w)-1<=idx;i++)
				st[w][i]=min(st[w-1][i],st[w-1][i+(1<<(w-1))]);
		build(1,1,n);
		return;
	}
}
namespace T1{
	int u[200005],v[200005],w[200005],first[100005],nxt[200005];
	void init(){
		qwq1.init();
		for (int i=1;i<n;i++){
			u[i]=qwq1.dfn[qwq1.u[i]],v[i]=qwq1.dfn[qwq1.v[i]],w[i]=qwq1.w[i];
			nxt[i]=first[u[i]],first[u[i]]=i;
			u[i+n]=v[i],v[i+n]=u[i],w[i+n]=w[i];
			nxt[i+n]=first[u[i+n]],first[u[i+n]]=i+n;
		}
		return;
	}
	int book[100005];
	int sz[100005],qwqn,rt;
	void getrt(int now,int fa){
		sz[now]=1;
		int mx=0;
		for (int i=first[now];i;i=nxt[i])
			if (v[i]!=fa&&book[v[i]]==0){
				getrt(v[i],now);
				sz[now]+=sz[v[i]];
				mx=max(mx,sz[v[i]]);
			}
		mx=max(mx,qwqn-sz[now]);
		if (2*mx<=qwqn)rt=now;
		return;
	}
	int tot,id[100005];
	ll sum[100005];
	void dfs(int now,int f,ll s){
		id[++tot]=now;
		sum[now]=s;
		for (int i=first[now];i;i=nxt[i])
			if (v[i]!=f&&book[v[i]]==0)dfs(v[i],now,s+w[i]);
		return;
	}
	ll ask(int x){
		int a=T2::tree[1].a,b=T2::tree[1].b;
		return max(T2::dis(x,a),T2::dis(x,b))-val[x];
	}
	void get_ans(int now){
		for (int i=0;i<(int)qid[now].size();i++){
			int id=qid[now][i];
			ans[id]=max(ans[id],sum[now]+ask(b[id])-inf);
		}
		return;
	}
	void work(int now){
		book[now]=1;
		getrt(now,0);
		tot=0;
		dfs(now,0,0);
		for (int i=1;i<=tot;i++){
			val[id[i]]=sum[id[i]]+inf;
			T2::upd(1,1,n,id[i]);
		}
		get_ans(now);
		for (int i=first[now];i;i=nxt[i]){
			if (book[v[i]]==1)continue;
			tot=0;
			dfs(v[i],now,w[i]);
			for (int j=1;j<=tot;j++){
				val[id[j]]=0;
				T2::upd(1,1,n,id[j]);
			}
			for (int j=1;j<=tot;j++)get_ans(id[j]);
			for (int j=1;j<=tot;j++){
				val[id[j]]=sum[id[j]]+inf;
				T2::upd(1,1,n,id[j]);
			}
		}
		tot=0;
		dfs(now,0,0);
		for (int i=1;i<=tot;i++){
			val[id[i]]=0;
			T2::upd(1,1,n,id[i]);
		}
		for (int i=first[now];i;i=nxt[i])
			if (book[v[i]]==0){
				qwqn=sz[v[i]];
				getrt(v[i],now);
				work(rt);
			}
		return;
	}
}
int main(){
	n=read(),q=read();
	T1::init();
	T2::init();
	for (int i=1;i<=q;i++){
		a[i]=qwq1.dfn[read()],b[i]=qwq2.dfn[read()];
		qid[a[i]].push_back(i);
	}
	T1::work(1);
	for (int i=1;i<=q;i++)printf("%lld\n",ans[i]);
	return 0;
}