// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;

vector<pair<int,long long>> adj[200005];
bool vis[200005];
int sz[200005];
vector<pair<int,long long>> dist[200005];

void dfs(int u, int p, long long d, int rt){
	dist[rt].push_back({u,d});
	for(auto [v,w] : adj[u]){
		if(v != p and !vis[v]){
			dfs(v,u,d+w,rt);
		}
	}
}

int dfs2(int u, int p){
	sz[u] = 1;
	for(auto [v,w] : adj[u]){
		if(v != p and !vis[v]){
			sz[u] += dfs2(v,u);
		}
	}
	return sz[u];
}

int centroid(int u, int p, int rootsz){
	for(auto [v,w] : adj[u]){
		if(v != p and !vis[p]){
			if(sz[v]*2 > rootsz){
				return centroid(v,u,rootsz);
			}
		}
	}
	return u;
}

void util(int u, int p){
	vis[u] = true;
	dfs2(u,u);
	int c = centroid(u,u,sz[u]);
	dfs(c,c,0,c);
	vis[c] = true;
	for(auto [v,w] : adj[c]){
		if(v != p and !vis[v]){
			util(v,c);
		}
	}
}

long long seg[800005];

void upd(int v, int l, int r, int pos, long long val){
	if(pos < l or pos > r){
		return ;
	}
	if(l == r){
		seg[v] = min(seg[v],val);
	}else{
		int mid = (l+r)/2;
		upd(v*2,l,mid,pos,val);
		upd(v*2+1,mid+1,r,pos,val);
		seg[v] = min(seg[v*2],seg[v*2+1]);
	}
}

long long query(int v, int l, int r, int ql, int qr){
	if(l > r or r < ql or l > qr){
		return 1e15;
	}
	if(l == ql and r == qr){
		//cout << "l=" << l << "r=" << r << "ql=" << ql << "qr=" << qr << endl;
		//cout << "RETURNING" << seg[v] << endl;
		return seg[v];
	}
	int mid = (l+r)/2;
	long long tmp1 = query(v*2,l,mid,ql,min(mid,qr));
	long long tmp2 = query(v*2+1,mid+1,r,max(ql,mid+1),qr);
	//cout << "l=" << l << "r=" << r << "ql=" << ql << "qr=" << qr << endl;
	//cout << "tmp1=" << tmp1 << "tmp2=" << tmp2 << endl;
	return min(tmp1,tmp2);
}

int main() {
	int n,q;
	cin >> n;
	for(int i = 1;i <= 4*n;i++){
		seg[i] = 1e15;
	}
	for(int i = 0;i < n-1;i++){
		long long a,b,c;
		cin >> a >> b >> c;
		adj[a].push_back({b,c});
		adj[b].push_back({a,c});
	}
	util(1,1);
	vector<array<long long,3>> bounds;
	for(int i = 1;i <= n;i++){
		sort(dist[i].begin(),dist[i].end());
		stack<pair<int,long long>> stk;
		for(auto [a,b] : dist[i]){
			while(!stk.empty() and stk.top().second > b){
				stk.pop();
			}
			if(!stk.empty()){
				bounds.push_back({stk.top().first,a,stk.top().second+b});
			}
			stk.push({a,b});
		}
		while(!stk.empty()){
			stk.pop();
		}
		reverse(dist[i].begin(),dist[i].end());
		for(auto [a,b] : dist[i]){
			while(!stk.empty() and stk.top().second > b){
				stk.pop();
			}
			if(!stk.empty()){
				bounds.push_back({a,stk.top().first,stk.top().second+b});
			}
			stk.push({a,b});
		}
	}
	sort(bounds.begin(),bounds.end());
	/*for(auto [a,b,c] : bounds){
		cout << a << " " << b << " " << c << endl;
	}*/
	cin >> q;
	array<int,3> qry[q];
	long long ans[q];
	for(int i = 0;i < q;i++){
		cin >> qry[i][0] >> qry[i][1];
		qry[i][2] = i;
	}
	sort(bounds.begin(),bounds.end());
	sort(qry,qry+q);
	int ind1 = q-1;
	int ind2 = bounds.size()-1;
	for(int i = n;i >= 1;i--){
		//cout << "i=" << i << endl;
		while(ind2 >= 0 and bounds[ind2][0] == i){
			//cout << "ind2=" << ind2 << " " << bounds[ind2][0] << " " << bounds[ind2][1] << " " << bounds[ind2][2] << endl;
			int tmp1 = bounds[ind2][1];
			long long tmp2 = query(1,1,n,tmp1,tmp1);
			//cout << "tmp=" << tmp1 << "tmp2=" << tmp2 << endl;
			upd(1,1,n,tmp1,bounds[ind2][2]); 
			ind2--;
		}
		//cout << endl;
		while(ind1 >= 0 and qry[ind1][0] == i){
			ans[qry[ind1][2]] = query(1,1,n,i,qry[ind1][1]);
			ind1--;
		}
		/*for(int j = 1;j <= n;j++){
			cout << query(1,1,n,j,j) << " ";
		}
		cout << endl;*/
	}
	for(int i = 0;i < q;i++){
		if(ans[i] >= 1e15){
			cout << -1 << endl;
			continue;
		}
		cout << ans[i] << endl;
	}
}