#include <iostream>
#include<algorithm>
#include<stdio.h>
#include<string.h>
#include<cmath>
using namespace std;
const int maxn=40010;
struct node
{
int to,next,w;
}edge[maxn<<1];
int head[maxn],cnt;
void addedge(int u,int v,int we)
{
edge[cnt].to=v ; edge[cnt].next=head[u];
edge[cnt].w=we; head[u]=cnt++;
}
bool vis[maxn];
int dis[maxn];
int deep[maxn<<1];
int ver[maxn<<1];
int pos[maxn];
int tot=0;
void dfs(int u,int step)
{
vis[u]=true;
ver[++tot]=u;pos[u]=tot;deep[tot]=step;
for(int i=head[u];i!=-1;i=edge[i].next)
{
int v=edge[i].to;
int w=edge[i].w;
if(!vis[v])
{
dis[v]=dis[u]+w;
dfs(v,step+1);
ver[++tot]=u,deep[tot]=step;
}
}
}
int dp[maxn<<1][30];
void st(int n)
{
int k=(int)(log((double)n)/log(2.0));
for(int i=1;i<=n;i++) dp[i][0]=i;
for(int j=1;j<=k;j++)
{
for(int i=1;i+(1<<j)-1<=n;++i)
{
int x=dp[i][j-1],y=dp[i+(1<<(j-1))][j-1];
if(deep[x]<deep[y]) dp[i][j]=x; else dp[i][j]=y;
}
}
}
int lca(int x,int y)
{
int a=pos[x],b=pos[y];
if(a>b) swap(a,b);
int k=(int)(log((double)(b-a+1))/log(2.0));
int l=dp[a][k],r=dp[b-(1<<k)+1][k];
return deep[l]<deep[r] ? ver[l]: ver[r];
}
void init()
{
cnt=0; tot=0;
memset(head,-1,sizeof(head));
memset(vis,0,sizeof(vis));
memset(dis,0,sizeof(dis));
}
int main()
{
int T;
scanf("%d",&T);
while(T--)
{
init();
int n,m;
scanf("%d%d",&n,&m);
for(int i=1;i<n;++i)
{
int u,v,w;
scanf("%d%d%d",&u,&v,&w);
addedge(u,v,w);
addedge(v,u,w);
}
dfs(1,1); st(tot);
while(m--)
{
int u,v;
scanf("%d%d",&u,&v);
long long ans=dis[u]+dis[v]-2*dis[lca(u,v)];
printf("%I64d\n",ans);
}
}
return 0;
}
