#include <iostream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cassert>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <utility>
#define llint long long
#define inf 1e18
#define rep(x, s, t) for(llint (x) = (s); (x) < (t); (x)++)
#define Rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++)
#define chmin(x, y) (x) = min((x), (y))
#define chmax(x, y) (x) = max((x), (y))
#define mod 1000000007

using namespace std;
typedef pair<llint, llint> P;

struct edge{
	llint to, cost;
	edge(){}
	edge(llint a, llint b){
		to = a, cost = b;
	}
};

llint n, Q;
vector<edge> G[100005];
set<P> S[100005];

int Prev[200005][18];
llint depth[200005], dist[200005], pcost[200005];
llint mini[200005][18];

int getLCA(int u, int v){
	int x = u, y = v;
	if(depth[y] > depth[x]) swap(x, y);
	
	for(int i = 17; i >= 0; i--){
		if(depth[x] - (1<<i) >= depth[y]) x = Prev[x][i];
	}
	if(x == y) return x;
	for(int i = 17; i >= 0; i--){
		if(Prev[x][i] != Prev[y][i]){
			x = Prev[x][i];
			y = Prev[y][i];
		}
	}
	x = Prev[x][0];
	return x;
}

void predfs(int v, int p, int d, llint s, llint pc)
{
	depth[v] = d, dist[v] = s, Prev[v][0] = p, pcost[v] = pc;
	for(int i = 0; i < G[v].size(); i++){
		if(G[v][i].to == p) continue;
		predfs(G[v][i].to, v, d+1, s + G[v][i].cost, G[v][i].cost);
		S[v].insert(P(G[v][i].cost, G[v][i].to));
	}
}

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	llint u, v, w;
	for(int i = 1; i <= n-1; i++){
		cin >> u >> v >> w;
		G[u].push_back(edge(v, w));
		G[v].push_back(edge(u, w));
	}
	
	predfs(1, 0, 0, 0, inf);
	for(int i = 1; i < 18; i++){
		for(int j = 1; j <= n; j++){
			Prev[j][i] = Prev[Prev[j][i-1]][i-1];
		}
	}
	
	for(int i = 1; i <= n; i++){
		llint p = Prev[i][0]; mini[i][0] = inf;
		if(p == 0) continue;
		for(auto it = S[p].begin(); it != S[p].end(); it++){
			if(it->second != v){
				mini[i][0] = it->first;
				break;
			}
		}
	}
	
	for(int i = 1; i < 18; i++){
		for(int j = 1; j <= n; j++){
			mini[j][i] = mini[j][i-1];
			if(Prev[j][i-1]) chmin(mini[j][i], mini[Prev[j][i-1]][i-1]);
		}
	}
	
	cin >> Q;
	llint x, y;
	for(int q = 0; q < Q; q++){
		cin >> x >> y;
		llint lca = getLCA(x, y), mn = inf, ans = dist[x]+dist[y]-2*dist[lca];
		//cout << "Q " << x << " " << y << endl;
		//cout << lca << " " << ans << endl;
		if(lca != x && lca != y){
			if(S[x].size()) mn = min(mn, S[x].begin()->first);
			if(S[y].size()) mn = min(mn, S[y].begin()->first);
			llint rem = depth[x] - depth[lca] - 1, v = x, w = y;
			for(int i = 17; i >= 0; i--){
				if(rem & (1<<i)){
					mn = min(mn, mini[v][i]);
					v = Prev[v][i];
				}
			}
			rem = depth[y] - depth[lca] - 1;
			for(int i = 17; i >= 0; i--){
				if(rem & (1<<i)){
					mn = min(mn, mini[w][i]);
					w = Prev[w][i];
				}
			}
			//cout << u << " " << v << endl;
			for(auto it = S[lca].begin(); it != S[lca].end(); it++){
				if(it->second != v && it->second != w){
					mn = min(mn, it->first);
					break;
				}
			}
			mn = min(mn, pcost[lca]);
		}
		else{
			if(lca == y) swap(x, y);
			if(S[y].size()) mn = min(mn, S[y].begin()->first);
			llint rem = depth[y] - depth[lca] - 1, w = y;
			for(int i = 17; i >= 0; i--){
				if(rem & (1<<i)){
					mn = min(mn, mini[w][i]);
					w = Prev[w][i];
				}
			}
			for(auto it = S[x].begin(); it != S[x].end(); it++){
				if(it->second != w){
					mn = min(mn, it->first);
					break;
				}
			}
			mn = min(mn, pcost[lca]);
		}
		if(mn > inf/2) cout << -1 << "\n";
		else{
			ans += mn*2;
			cout << ans << "\n";
		}
	}
	flush(cout);
	
	return 0;
}