#include<cstdio>

#include<cstring>

#include<vector>

#include<algorithm>

using namespace std;

const int maxn=40000+3;

typedef long long ll;

ll dis[maxn];

int son[maxn],siz[maxn],rank1[maxn],p[maxn],top[maxn];

struct Edge {

	int from, to, dis;

	Edge(int from, int to, int dis) :from(from), to(to), dis(dis){}

};

struct LCA{

	vector<Edge>edges;

	vector<int>G[maxn];

	void init(int n){

		for(int i=1;i<=n;++i)G[i].clear();

		edges.clear();

		memset(son,-1,sizeof(son));memset(dis,0,sizeof(dis));

		memset(rank1,0,sizeof(rank1));memset(p,0,sizeof(p));

		memset(siz,0,sizeof(siz));memset(top,0,sizeof(top));

	}

	void add_edge(int from,int to,int dis){

		edges.push_back(Edge(from,to,dis));

		int m=edges.size()-1;

		G[from].push_back(m);

	}

	void dfs1(int u,int fa,int cur,ll dep)

	{

		siz[u]=1,p[u]=fa,rank1[u]=cur;

        dis[u]=dep;

        for(int i=0;i<G[u].size();++i)

        {

        	int m=G[u][i];

        	Edge E=edges[m];

        	if(E.to!=fa)

        	{

	        	dfs1(E.to,u,cur+1,dep+E.dis);

	        	siz[u]+=siz[E.to];

	        	if(son[u]==-1||siz[son[u]]<siz[E.to])son[u]=E.to;

	        }

        }

	}

	void dfs2(int u,int tp){

		top[u]=tp;

		if(son[u]!=-1)dfs2(son[u],tp);

		for(int i=0;i<G[u].size();++i)

		{

			int m=G[u][i];

			Edge E=edges[m];

			if(E.to!=p[u]&&E.to!=son[u])dfs2(E.to,E.to);

		}

	}

	int query(int x,int y)

	{

		while(top[x]!=top[y])

		{

			if(rank1[top[x]]<=rank1[top[y]])y=p[top[y]];

			else x=p[top[x]];

		}

		if(rank1[x]<=rank1[y])return x;

		return y;

	}

	ll ans(int x,int y)

	{

		ll m1=dis[x],m2=dis[y];

		int lca=query(x,y);

		return m1+m2-2*dis[lca];

	}

};

int main(){

	int T;scanf("%d",&T);

    while(T--)

    {

    	int n,m;scanf("%d%d",&n,&m);

    	LCA _lca;

    	_lca.init(n);

		for(int i=1;i<n;++i)

		{

		   int from,to,dis;

		   scanf("%d%d%d",&from,&to,&dis);

		   _lca.add_edge(from,to,dis);

		   _lca.add_edge(to,from,dis);

		}

		_lca.dfs1(1,-1,1,0);

		_lca.dfs2(1,1);

		for(int i=1;i<=m;++i)

		{

			int a,b;scanf("%d%d",&a,&b);

			printf("%lld\n",_lca.ans(a,b));

		}

    }

    return 0;

}