#pragma GCC optimize(fast)
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
#define int long long
#define PII pair <int,int>
#define lowbit(x) (x&(-x))
#define N 1000010
const int INF=1e18;
int n,m,tot,head[N];
int idx,dfn[N],anc[21][N],dep[N],dist[N];
int root,MinSize,AllSize,siz[N],maxsiz[N],vis[N];
int cnt,buc[N],top,st[N],ans[N];
vector <int> vecT[N];
vector < PII > vecQ[N];
//注意，此处存的二元组(x,y)保证x>y，方便根据右端点排序 
struct NodeA
{
	int nxt,to,val;
}edge[N<<1];

struct NodeB
{
	int minv[N];
	
	void Clear ()
	{
		for (int i=1;i<=n;i++)
			minv[i]=INF;
	}
	
	void Update (int x,int val)
	{
		while (x<=n)
		{
			minv[x]=min (minv[x],val);
			x+=lowbit (x);
		}
	}
	
	int Query (int x)
	{
		int res=INF;
		while (x>0)
		{
			res=min (res,minv[x]);
			x-=lowbit (x);
		}
		return res;
	}
	
}BIT;

int read ()
{
	int k=1,s=0;char ch=getchar ();
	while (!isdigit (ch)) {if (ch=='-') k=-1;ch=getchar ();}
	while (isdigit (ch)) {s=s*10+ch-'0';ch=getchar ();}
	return k*s;
}

void AddEdge (int x,int y,int w)
{
	edge[++tot]=(NodeA) {head[x],y,w};
	head[x]=tot;
}

void FindRoot (int x,int from)
{	
	siz[x]=1;
	maxsiz[x]=0;
	for (int i=head[x];i;i=edge[i].nxt)
	{
		int y=edge[i].to;
		if (y==from || vis[y]) continue;
		FindRoot (y,x);
		siz[x]+=siz[y];
		maxsiz[x]=max (maxsiz[x],siz[y]); 
	}
	maxsiz[x]=max (maxsiz[x],AllSize-siz[x]);
	if (maxsiz[x]<MinSize)
	{
		MinSize=maxsiz[x];
		root=x;
	}
}

void FindSon (int x,int from)
{
	buc[++cnt]=x;
	for (int i=head[x];i;i=edge[i].nxt)
	{
		int y=edge[i].to;
		if (y==from || vis[y]) continue;
		FindSon (y,x);
	}
}

void DFS1 (int x,int from)
{
	dep[x]=dep[from]+1;
	anc[0][dfn[x]=++idx]=from;
	siz[x]=1;
	for (int i=head[x];i;i=edge[i].nxt)
	{
		int y=edge[i].to,w=edge[i].val;
		if (y==from) continue;
		dist[y]=dist[x]+w;
		DFS1 (y,x);
		siz[x]+=siz[y];
	}
}

int Getmin (int x,int y)
{
	return dfn[x]<dfn[y]?x:y;
}

int GetLCA (int x,int y)
{
	if (x==y) return x;
	if (dfn[x]>dfn[y]) swap (x,y);
	x=dfn[x]+1,y=dfn[y];
	int k=log2 (y-x+1);
	return Getmin (anc[k][x],anc[k][y-(1<<k)+1]);
}

void GetST ()
{
	for (int k=1;k<=20;k++)
		for (int i=1;i+(1<<k)-1<=n;i++)
			anc[k][i]=Getmin (anc[k-1][i],anc[k-1][i+(1<<(k-1))]);
}

int GetDist (int x,int y)
{
	int z=GetLCA (x,y);
	return dist[x]+dist[y]-2*dist[z];
}

void DFS2 (int x)
{
	vis[x]=1;
	cnt=0;
	buc[++cnt]=x;
	for (int i=head[x];i;i=edge[i].nxt)
	{
		int y=edge[i].to;
		if (vis[y]) continue;
		FindSon (y,x);
	}
	sort (buc+1,buc+1+cnt);
	top=0;
	for (int i=1;i<=cnt;i++)
	{
		while (top>0 && GetDist (x,st[top])>GetDist (x,buc[i])) top--;
		if (top>0) vecT[st[top]].push_back (buc[i]);
		st[++top]=buc[i];
	}
	reverse (buc+1,buc+1+cnt);
	top=0;
	for (int i=1;i<=cnt;i++)
	{
		while (top>0 && GetDist (x,st[top])>GetDist (x,buc[i])) top--;
		if (top>0) vecT[buc[i]].push_back (st[top]);
		st[++top]=buc[i];
	}
	for (int i=head[x];i;i=edge[i].nxt)
	{
		int y=edge[i].to;
		if (vis[y]) continue;
		root=0,AllSize=siz[y],MinSize=siz[y];
		FindRoot (root,0);
		DFS2 (y);
	}
}

void Init ()
{
	n=read ();
	for (int i=1;i<n;i++)
	{
		int x=read (),y=read (),w=read ();
		AddEdge (x,y,w);
		AddEdge (y,x,w); 
	}
	m=read ();
	for (int i=1;i<=m;i++)
	{
		int l=read (),r=read ();
		vecQ[l].push_back (make_pair (r,i));
	} 
}

void Work ()
{
	root=0,MinSize=n,AllSize=n;
	FindRoot (1,0);
	DFS1 (root,0);
	GetST ();
	DFS2 (root);
	BIT.Clear (); 
	for (int i=n;i>=1;i--)
	{
		for (int j=0;j<vecT[i].size ();j++)
		{
			int k=vecT[i][j];
			BIT.Update (k,GetDist (k,i));
		}
		for (int j=0;j<vecQ[i].size ();j++)
		{
			int k=vecQ[i][j].first,id=vecQ[i][j].second;
			ans[id]=BIT.Query (k);
		}
	}
	for (int i=1;i<=m;i++)
		if (ans[i]!=INF) printf ("%lld\n",ans[i]);
		else printf ("-1\n");
}

signed main ()
{
	Init ();
	Work ();
	return 0;
}