#include<bits/stdc++.h>
using namespace std;
using ll=long long;
template<typename T>
ostream& operator << (ostream &out,const vector<T>&x){
	if(x.empty())return out<<"[]";
	out<<'['<<x[0];
	for(int len=x.size(),i=1;i<len;i++)out<<','<<x[i];
	return out<<']';
}
template<typename T>
vector<T> ary(const T *a,int l,int r){
	return vector<T>{a+l,a+1+r};
}
template<typename T>
void debug(T x){
	cerr<<x<<'\n';
}
template<typename T,typename ...S>
void debug(T x,S ...y){
	cerr<<x<<' ',debug(y...);
}
const int N=2e5+10,M=1e6+10;
const ll INF=1e18;
int n,m;
vector<pair<int,int> >to[N];
#define v e.first
#define w e.second
int cnt,rt,siz[N],mx[N],vis[N];
void dfs1(int u,int fa=0){
	cnt++;
	for(auto e:to[u])if(v^fa&&!vis[v]){
		dfs1(v,u);
	}
}
void dfs2(int u,int fa=0){
	siz[u]=1,mx[u]=0;
	for(auto e:to[u])if(v^fa&&!vis[v]){
		dfs2(v,u);
		siz[u]+=siz[v];
		mx[u]=max(mx[u],siz[v]);
	}
	mx[u]=max(mx[u],m-siz[u]);
	if(mx[u]<mx[rt])rt=u;
}
vector<pair<int,ll> >d;
void dfs3(int u,int fa=0,ll dis=0){
	d.push_back({u,dis});
	for(auto e:to[u])if(v^fa)dfs3(v,u,dis+w);
}
int top,stk[N];
vector<pair<int,ll> >o[N];
vector<pair<int,int> >q[N];
ll ans[M];
void update(int x,int y,ll z){
	if(x>y)swap(x,y);
	o[x].push_back({y,z});
}
void insert(){
	top=0;
	for(int len=d.size(),i=0;i<len;i++){
		for(;top;top--){
			update(d[stk[top]].first,d[i].first,d[stk[top]].second+d[i].second);
			if(d[stk[top]].second<=d[i].second)break;
		}
		stk[++top]=i;
	}
}
void solve(int u){
	cnt=rt=0,dfs1(u),dfs2(u),vis[u=rt]=1;
	d.clear(),dfs3(u);
	sort(d.begin(),d.end());
	insert();
	reverse(d.begin(),d.end());
	insert();
	for(auto e:to[u])if(!vis[v])solve(v);
}
#undef v
#undef w
ll c[N];
void add(int x,ll y){
	for(;x<=n&&c[x]>y;x+=x&-x)c[x]=y;
}
ll get(int x,ll y=INF){
	for(;x;x^=x&-x)y=min(y,c[x]);
	return y;
}
int main(){
	scanf("%d",&n);
	for(int u,v,w,i=1;i<n;i++){
		scanf("%d%d%d",&u,&v,&w);
		to[u].push_back({v,w}),to[v].push_back({u,w});
	}
	mx[0]=n+1,solve(1);
	scanf("%d",&m);
	for(int i=1,l,r;i<=m;i++){
		scanf("%d%d",&l,&r);
		q[l].push_back({r,i});
	}
	fill(c+1,c+1+n,INF);
	for(int i=n;i>=1;i--){
		for(auto ot:o[i])add(ot.first,ot.second);
		for(auto qt:q[i])ans[qt.second]=get(qt.first);
	}
	for(int i=1;i<=m;i++)printf("%lld\n",ans[i]<INF?ans[i]:-1);
	return 0;
}