#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
#define N 200000
#define M 1000000
using namespace std;
const int inf=(int)(1e9);
const long long INF=(long long)(1e18);
int read()
{
	char c=0;
	int sum=0;
	while (c<'0'||c>'9') c=getchar();
	while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
	return sum;
}
struct reads
{
	int num;
	long long data;
	bool operator < (const reads &t)const
	{
		return num<t.num;	
	}
};
reads tong[N+1];
int n,q,rt,leng,length,smz,sz[N+1],szt[N+1],maxp[N+1],dque[N+1],top;
long long dis[N+1],ans[M+1],c[N+1];
vector<reads>E[N+1];
vector<reads>p[N+1];
vector<reads>v[N+1];
bool used[N+1],vis[N+1];
void add(int x,int y,int z)
{
	E[x].push_back((reads){y,z}),E[y].push_back((reads){x,z});
	return;
}
void get_rt(int x)
{
	vis[x]=sz[x]=1,maxp[x]=0;
	for (int i=0;i<E[x].size();++i)
		if (!used[E[x][i].num]&&!vis[E[x][i].num])
			get_rt(E[x][i].num),sz[x]+=sz[E[x][i].num],maxp[x]=max(maxp[x],sz[E[x][i].num]);
	maxp[x]=max(maxp[x],smz-sz[x]);
	if (maxp[x]<maxp[rt]) rt=x;
	vis[x]=0;
	return;
}
void dfs(int x)
{
	vis[x]=szt[x]=1,tong[++length]=(reads){x,dis[x]};
	for (int i=0;i<E[x].size();++i)
		if (!used[E[x][i].num]&&!vis[E[x][i].num])
			dis[E[x][i].num]=dis[x]+E[x][i].data,dfs(E[x][i].num),szt[x]+=szt[E[x][i].num];	
	return;
}
void solve(int x)
{
	used[x]=1,dis[x]=0,tong[length=1]=(reads){x,0};
	for (int i=0;i<E[x].size();++i)
		if (!used[E[x][i].num])
			dis[E[x][i].num]=E[x][i].data,dfs(E[x][i].num);
	sort(tong+1,tong+length+1),top=0;
	for (int i=1;i<=length;++i)
	{
		while (top&&tong[dque[top]].data>=tong[i].data) top--;
		if (top) p[tong[i].num].push_back((reads){tong[dque[top]].num,tong[dque[top]].data+tong[i].data});
		dque[++top]=i;
	}
	top=0;
	for (int i=length;i>=1;--i)
	{
		while (top&&tong[dque[top]].data>tong[i].data) top--;
		if (top) p[tong[dque[top]].num].push_back((reads){tong[i].num,tong[i].data+tong[dque[top]].data});
		dque[++top]=i;
	}
	for (int i=0;i<E[x].size();++i)
		if (!used[E[x][i].num])
			smz=szt[E[x][i].num],rt=0,get_rt(E[x][i].num),solve(rt);
	return;
}
int lowbit(int x)
{
	return x&(-x);
}
void add(int x,long long d)
{
	for (;x<=n;x+=lowbit(x)) c[x]=min(c[x],d);
	return;
}
long long query(int x)
{
	long long res=INF;
	for (;x>=1;x-=lowbit(x)) res=min(res,c[x]);
	return res;
}
int main()
{
	int x,y,z,l,r;
	n=read(),maxp[0]=inf;
	for (int i=1;i<=n;++i) c[i]=INF;
	for (int i=1;i<=n-1;++i) x=read(),y=read(),z=read(),add(x,y,z);
	q=read();
	for (int i=1;i<=q;++i)
	{
		l=read(),r=read();
		if (l==r) ans[i]=-1;
		else v[r].push_back((reads){l,i});
	}
	smz=n,get_rt(1),solve(rt);
	for (int i=1;i<=n;++i)
	{
		for (int j=0;j<p[i].size();++j) add(n-p[i][j].num+1,p[i][j].data);
		for (int j=0;j<v[i].size();++j) ans[v[i][j].data]=query(n-v[i][j].num+1);
	}
	for (int i=1;i<=q;++i) printf("%lld\n",ans[i]);
	return 0;
}