#include<bits/stdc++.h>
using namespace std;
namespace my_std{
	#define ll long long
	#define bl bool
	ll my_pow(ll a,ll b,ll mod){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res=(res*a)%mod;
			a=(a*a)%mod;
			b>>=1;
		}
		return res;
	}
	ll qpow(ll a,ll b){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res*=a;
			a*=a;
			b>>=1;
		}
		return res;
	}
	#define db double
	#define pf printf
	#define pc putchar
	#define fr(i,x,y) for(register ll i=(x);i<=(y);i++)
	#define pfr(i,x,y) for(register ll i=(x);i>=(y);i--)
	#define go(u) for(ll i=head[u];i;i=e[i].nxt)
	#define enter pc('\n')
	#define space pc(' ')
	#define fir first
	#define sec second
	#define MP make_pair
	#define il inline
	#define inf 8e18
	#define random(x) rand()*rand()%(x)
	#define inv(a,mod) my_pow((a),(mod-2),(mod))
	il ll read(){
		ll sum=0,f=1;
		char ch=0;
		while(!isdigit(ch)){
			if(ch=='-') f=-1;
			ch=getchar();
		}
		while(isdigit(ch)){
			sum=sum*10+(ch^48);
			ch=getchar();
		}
		return sum*f;
	}
	il void write(ll x){
		if(x<0){
			x=-x;
			pc('-');
		}
		if(x>9) write(x/10);
		pc(x%10+'0');
	}
	il void writeln(ll x){
		write(x);
		enter;
	}
	il void writesp(ll x){
		write(x);
		space;
	}
}
using namespace my_std;
#define LC x<<1
#define RC x<<1|1
ll n,q,now,ans[100010][2];
ll tree[400040][2];
struct edge{
	ll nxt,to,w;
};
struct tree{
	ll head[100010],cnt=0,dfn[100010],st[100010],ed[100010],tot=0,dep[100010];
	ll minn[100010][18],lg[100010];
	edge e[200020];
	void add(ll u,ll v,ll ww){
		e[++cnt].nxt=head[u];
		e[cnt].to=v;
		e[cnt].w=ww;
		head[u]=cnt;
	}
	void dfs(ll fa,ll u){
		dfn[++tot]=u;
		st[u]=tot;
		go(u){
			ll v=e[i].to;
			if(v==fa) continue;
			dep[v]=dep[u]+e[i].w;
			dfs(u,v);
		}
		ed[u]=tot;
	}
	void init(){
		dfs(0,1);
		lg[1]=0;
		fr(i,2,n) lg[i]=lg[i>>1]+1;
		fr(i,1,n) minn[i][0]=dep[dfn[i]];
		fr(j,1,17) fr(i,1,n-(1ll<<j)+1) minn[i][j]=min(minn[i][j-1],minn[i+(1ll<<(j-1))][j-1]);
	}
	il ll dis(ll x,ll y){
		ll l=st[x],r=st[y];
		if(l>r) swap(l,r);
		ll tmp=lg[r-l+1];
		return dep[x]+dep[y]-2*min(minn[l][tmp],minn[r-(1ll<<tmp)+1][tmp]);
	}
}T1,T2;
il ll calc(ll x,ll y){
	return T2.dis(x,y)+T1.dis(now,x)+T1.dis(now,y);
}
il void pushup(ll x){
	ll maxx=-inf;
	fr(i,0,1){
		fr(j,0,1){
			ll tmp=calc(tree[LC][i],tree[RC][j]);
			if(tmp>maxx){
				maxx=tmp;
				tree[x][0]=tree[LC][i];
				tree[x][1]=tree[RC][j];
			}
		}
	}
}
void build(ll x,ll l,ll r){
	if(l==r){
		tree[x][0]=tree[x][1]=T1.dfn[l];
		return;
	}
	ll mid=(l+r)>>1;
	build(LC,l,mid);
	build(RC,mid+1,r);
	pushup(x);
}
void mdf(ll x,ll l,ll r,ll ql,ll qr){
	if(r<ql||l>qr||(ql<=l&&r<=qr)) return;
	ll mid=(l+r)>>1;
	mdf(LC,l,mid,ql,qr);
	mdf(RC,mid+1,r,ql,qr);
	pushup(x);
}
void dfs(ll fa,ll u){
	ans[u][0]=tree[1][0];
	ans[u][1]=tree[1][1];
	for(ll i=T1.head[u];i;i=T1.e[i].nxt){
		ll v=T1.e[i].to;
		if(v==fa) continue;
		now=v;
		mdf(1,1,n,T1.st[v],T1.ed[v]);
		dfs(u,v);
		now=u;
		mdf(1,1,n,T1.st[v],T1.ed[v]);
	}
}
int main(){
	n=read();
	q=read();
	fr(i,2,n){
		ll u=read(),v=read(),w=read();
		T1.add(u,v,w);
	}
	fr(i,2,n){
		ll u=read(),v=read(),w=read();
		T2.add(u,v,w);
	}
	T1.init();
	T2.init();
	now=1;
	build(1,1,n);
	dfs(0,1);
	while(q--){
		ll a=read(),b=read();
		writeln(max(T1.dis(a,ans[a][0])+T2.dis(b,ans[a][0]),T1.dis(a,ans[a][1])+T2.dis(b,ans[a][1])));
	}
}