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

namespace FastIO
{

class FastIOBase
{
 protected:
#ifdef OPENIOBUF
	static const int BUFSIZE=1<<22;
	char buf[BUFSIZE+1];
	int buf_p=0;
#endif
	FILE *target;
 public:
#ifdef OPENIOBUF
	virtual void flush()=0;
#endif
	FastIOBase(FILE *f): target(f){}
	~FastIOBase()=default;
};

class FastOutput: public FastIOBase
{
#ifdef OPENIOBUF
 public:
	inline void flush()
		{ fwrite(buf,1,buf_p,target),buf_p=0; }
#endif
 protected:
	inline void __putc(char x)
	{
#ifdef OPENIOBUF
		if(buf[buf_p++]=x,buf_p==BUFSIZE)flush();
#else
		putc(x,target);
#endif
	}
	template<typename T>
	inline void __write(T x)
	{
		static char stk[64],*top;top=stk;
		if(x<0) return __putc('-'),__write(-x);
		do *(top++)=x%10,x/=10; while(x);
		for(;top!=stk;__putc(*(--top)+'0'));
	}
 public:
	FastOutput(FILE *f=stdout): FastIOBase(f){}
#ifdef OPENIOBUF
	inline void setTarget(FILE *f) { this->flush(),target=f; }
	~FastOutput(){ flush(); }
#else
	inline void setTarget(FILE *f) { target=f; }
#endif
	template<typename ...T>
	inline void writesp(const T &...x)
		{ initializer_list<int>{(this->operator<<(x),__putc(' '),0)...}; }
	template<typename ...T>
	inline void writeln(const T &...x)
		{ initializer_list<int>{(this->operator<<(x),__putc('\n'),0)...}; }
	inline FastOutput &operator <<(char x)
		{ return __putc(x),*this; }
	inline FastOutput &operator <<(const char *s)
		{ for(;*s;__putc(*(s++)));return *this; }
	inline FastOutput &operator <<(const string &s)
		{ return (*this)<<s.c_str(); }
	template<typename T,typename=typename enable_if<is_integral<T>::value>::type>
	inline FastOutput &operator <<(const T &x)
		{ return __write(x),*this; }
}qout;

class FastInput: public FastIOBase
{
#ifdef OPENIOBUF
 public:
	inline void flush()
		{ buf[fread(buf,1,BUFSIZE,target)]='\0',buf_p=0; }
#endif
 protected:
	inline char __getc()
	{
#ifdef OPENIOBUF
		if(buf_p==BUFSIZE) flush();
		return buf[buf_p++];
#else
		return getc(target);
#endif
	}
 public:
#ifdef OPENIOBUF
	FastInput(FILE *f=stdin): FastIOBase(f){ buf_p=BUFSIZE; }
	inline void setTarget(FILE *f) { this->flush(),target=f; }
#else
	FastInput(FILE *f=stdin): FastIOBase(f){}
	inline void setTarget(FILE *f) { target=f; }
#endif
	inline char getchar() { return __getc(); }
	template<typename ...T>
	inline void read(T &...x)
		{ initializer_list<int>{(this->operator>>(x),0)...}; }
	inline FastInput &operator >>(char &x)
		{ while(isspace(x=__getc()));return *this; }
	template<typename T,typename=typename enable_if<is_integral<T>::value>::type>
	inline FastInput &operator >>(T &x)
	{
		static char ch,sym;x=sym=0;
		while(isspace(ch=__getc()));
		if(ch=='-') sym=1,ch=__getc();
		for(;isdigit(ch);x=(x<<1)+(x<<3)+(ch^48),ch=__getc());
		return sym?x=-x:x,*this;
	}
	inline FastInput &operator >>(char *s)
	{
		while(isspace(*s=__getc()));
		for(;!isspace(*s) && *s && ~*s;*(++s)=__getc());
		return *s='\0',*this;
	}
	inline FastInput &operator >>(string &s)
	{
		char str_buf[(1<<8)+1],*p=str_buf;
		char *const buf_end=str_buf+(1<<8);
		while(isspace(*p=__getc()));
		for(s.clear(),p++;;p=str_buf)
		{
			for(;p!=buf_end && !isspace(*p=__getc()) && *p && ~*p;p++);
			*p='\0',s.append(str_buf);
			if(p!=buf_end) break;
		}
		return *this;
	}
}qin;

} // namespace FastIO
using namespace FastIO;

using LL=long long;
using LD=long double;
using UI=unsigned int;
using ULL=unsigned long long;

#ifndef DADALZY
#define FILEIO(file) freopen(file".in","r",stdin),freopen(file".out","w",stdout)
#else
#define FILEIO(file)
#endif

int n,q;
vector<pair<int,int>> g1[100005],g2[100005];
LL d1[100005],d2[100005];
int dfn,lb[100005],rb[100005],ord[100005];
int nn,dep[100005],pos[100005],eul[200005],f[200005][20];

void dfs1(int u,int fa=0)
{
	ord[++dfn]=u,lb[u]=dfn;
	for(auto &[v,w]: g1[u])
	{
		if(v==fa) continue;
		d1[v]=d1[u]+w;
		dfs1(v,u);
	}
	rb[u]=dfn;
}
void dfs2(int u,int fa=0)
{
	dep[u]=dep[fa]+1;
	eul[pos[u]=++nn]=u;
	for(auto &[v,w]: g2[u])
	{
		if(v==fa) continue;
		d2[v]=d2[u]+w;
		dfs2(v,u),eul[++nn]=u;
	}
}
inline bool cmpd(int x,int y) { return dep[x]<dep[y]; }
void prework()
{
	for(int i=1;i<=nn;i++) f[i][0]=eul[i];
	for(int j=1;(1<<j)<=nn;j++)
		for(int i=1;i+(1<<j)-1<=nn;i++)
			f[i][j]=min(f[i][j-1],f[i+(1<<(j-1))][j-1],cmpd);
}
inline int lca(int u,int v)
{
	tie(u,v)=minmax(pos[u],pos[v]);
	int s=__lg(v-u+1);
	return min(f[u][s],f[v-(1<<s)+1][s],cmpd);
}
inline LL dis(int u,int v)
{
	int l=lca(u,v);
	return d2[u]+d2[v]-2*d2[l];
}

struct TreeNode{ array<LL,2> u,w;LL mx,tag; }t[400005];
#define LC (i<<1)
#define RC (i<<1|1)
inline void pushTag(int i,LL x)
{
	t[i].tag+=x;
	t[i].mx+=(x<<1);
	t[i].w[0]+=x,t[i].w[1]+=x;
}
inline void pushdown(int i)
{
	if(!t[i].tag) return;
	pushTag(LC,t[i].tag);
	pushTag(RC,t[i].tag);
	t[i].tag=0;
}
inline void pushup(int i)
{
	if(t[LC].mx>t[RC].mx) t[i].u=t[LC].u,t[i].w=t[LC].w,t[i].mx=t[LC].mx;
	else t[i].u=t[RC].u,t[i].w=t[RC].w,t[i].mx=t[RC].mx;
	for(int k1: {0,1}) for(int k2: {0,1})
	{
		int tmp=dis(t[LC].u[k1],t[RC].u[k2])+t[LC].w[k1]+t[RC].w[k2];
		if(tmp<=t[i].mx) continue;
		t[i].mx=tmp;
		t[i].u={t[LC].u[k1],t[RC].u[k2]};
		t[i].w={t[LC].w[k1],t[RC].w[k2]};
	}
}
void build(int l,int r,int i=1)
{
	if(l==r)
	{
		int x=ord[l];
		t[i].u={x,x},t[i].mx=d1[x]<<1;
		t[i].w={d1[x],d1[x]};
		return;
	}
	int mid=(l+r)>>1;
	build(l,mid,LC),build(mid+1,r,RC);
	pushup(i);
}
void modify(int lq,int rq,LL x,int i=1,int l=1,int r=n)
{
	if(l>=lq && r<=rq) return pushTag(i,x);
	int mid=(l+r)>>1;
	pushdown(i);
	if(mid>=lq) modify(lq,rq,x,LC,l,mid);
	if(mid<rq) modify(lq,rq,x,RC,mid+1,r);
	pushup(i);
}

vector<pair<int,int>> ask[100005];
LL ans[500005];
void solve(int u,int fa=0)
{
	for(auto &[v,id]: ask[u])
		ans[id]=max(dis(t[1].u[0],v)+t[1].w[0],
					dis(t[1].u[1],v)+t[1].w[1]);
	for(auto &[v,w]: g1[u])
	{
		if(v==fa) continue;
		modify(lb[v],rb[v],-w);
		if(lb[v]>1) modify(1,lb[v]-1,w);
		if(rb[v]<n) modify(rb[v]+1,n,w);
		solve(v,u);
		modify(lb[v],rb[v],w);
		if(lb[v]>1) modify(1,lb[v]-1,-w);
		if(rb[v]<n) modify(rb[v]+1,n,-w);
	}
}
int main()
{
	qin>>n>>q;
	for(int i=1,u,v,w;i<n;i++)
	{
		qin>>u>>v>>w;
		g1[u].emplace_back(v,w);
		g1[v].emplace_back(u,w);
	}
	for(int i=1,u,v,w;i<n;i++)
	{
		qin>>u>>v>>w;
		g2[u].emplace_back(v,w);
		g2[v].emplace_back(u,w);
	}
	dfs1(1),dfs2(1);
	prework(),build(1,n);
	for(int i=1,u,v;i<=q;i++)
	{
		qin>>u>>v;
		ask[u].emplace_back(v,i);
	}
	solve(1);
	for(int i=1;i<=q;i++) qout<<ans[i]<<'\n';
	return 0;
}