#include<cstdio>

#include<cctype>

#include<cstring>

#include<iostream>

using namespace std;

inline long long read(){

    long long num=,f=;

    char ch=getchar();

    while(!isdigit(ch)){

        if(ch=='-')    f=-;

        ch=getchar();

    }

    while(isdigit(ch)){

        num=num*+ch-'';

        ch=getchar();

    }

    return num*f;

}

struct Edge{

    int next,to,dis;

};

struct Pic{

    Edge edge[];

    int head[],num;

    bool vis[];

    inline void add(int from,int to,int dis){

        edge[++num]=(Edge){head[from],to,dis};

        head[from]=num;

    }

}pic,que;

int dst[];

int ans[][];

bool vis[];

int father[];

int find(int x){    return x==father[x]? x:father[x]=find(father[x]);    }

int unionn(int x,int y){    father[find(y)]=find(x);    }

void dfs(int x){

    vis[x]=;

    for(int i=pic.head[x];i;i=pic.edge[i].next){

        if(vis[pic.edge[i].to])    continue;

        dst[pic.edge[i].to]=dst[x]+pic.edge[i].dis;

        dfs(pic.edge[i].to);

        unionn(x,pic.edge[i].to);

    }

    for(int i=que.head[x];i;i=que.edge[i].next)

        if(vis[que.edge[i].to])

            ans[x][que.edge[i].to]=ans[que.edge[i].to][x]=dst[x]+dst[que.edge[i].to]-(dst[find(que.edge[i].to)]<<);

}

int a[],b[];

int main(){

    int n=read(),q=read();

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

        int from=read(),to=read(),dis=read();

        pic.add(from,to,dis);pic.add(to,from,dis);

        father[i]=i;

    }

    father[n]=n;

    for(int i=;i<=q;++i){

        int from=read(),to=read();

        a[i]=from;b[i]=to;

        que.add(from,to,);

        que.add(to,from,);

    }

    dfs();

    for(int i=;i<=q;++i)    printf("%d\n",ans[a[i]][b[i]]);

    return ;

}