#include<bits/stdc++.h>
using namespace std;
vector<vector<pair<int, int> > > adj;
int n, q;
vector<int> bit;
vector<pair<int, int> > order;
vector<bool> visited;
vector<int> sz;
vector<int> maxSz;
vector<vector<pair<int, int> > > values;
void dfs(int u, int p, int cur, int& curRoot){
	sz[u] = 1;
    maxSz[u] = 0;
    for(pair<int, int> v : adj[u]){
        if(v.first != p && !visited[v.first]){
            dfs(v.first, u, cur, curRoot);
            maxSz[u] = max(maxSz[u], sz[v.first]);
            sz[u] += sz[v.first];
        }
    }
    maxSz[u] = max(maxSz[u], cur - sz[u]);
    if(curRoot == 0){
        curRoot = u;
    }
    if(maxSz[u] < maxSz[curRoot]){
        curRoot = u;
    }
}
void update(int x, int val){
	while(x <= n){
        bit[x] = min(bit[x], val);
        x += x & -x;
    }
}
int query(int x){
	int ans = INT_MAX;
	while(x != 0){
        ans = min(ans, bit[x]);
        x -= x & -x;
    }
	return ans;
}
void dfs2(int u, int p, int sum){
    order.push_back(make_pair(u, sum));
    for(pair<int, int> v : adj[u]){
        if(v.first != p && !visited[v.first]){
            dfs2(v.first, u, sum + v.second);
        }
    }
}
void dfs3(int u){
    int curRoot = 0;
    dfs(u, 0, sz[u], curRoot);
    u = curRoot;
    visited[u] = true;
    order.clear();
    dfs2(u, 0, 0);
    sort(order.begin(), order.end());
    stack<int> curStack;
    for(int i = 0; i < (int)order.size(); i++){
        while(!curStack.empty() && order[i].second < order[curStack.top()].second){
            curStack.pop();
        }
        if(!curStack.empty()){
            values[order[i].first].push_back(make_pair(order[curStack.top()].first, order[i].second + order[curStack.top()].second));
        }
        curStack.push(i);
    }
    while(!curStack.empty()){
        curStack.pop();
    }
    for(int i = (int)order.size() - 1; i >= 0; i--){
        while(!curStack.empty() && order[i].second < order[curStack.top()].second){
            curStack.pop();
        }
        if(!curStack.empty()){
            values[order[curStack.top()].first].push_back(make_pair(order[i].first, order[i].second + order[curStack.top()].second));
        }
        curStack.push(i);
    }
    for(pair<int, int> v : adj[u]){
        if(!visited[v.first]){
            dfs3(v.first);
        }
    }
}
int main(){
    cin >> n;
    adj.resize(1 + n);
    bit.resize(1 + n);
    visited.resize(1 + n);
    sz.resize(1 + n);
    maxSz.resize(1 + n);
    values.resize(1 + n);
    for(int i = 1; i < n; i++){
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back(make_pair(v, w));
        adj[v].push_back(make_pair(u, w));
    }
    for(int i = 1; i <= n; i++){
        bit[i] = INT_MAX;
    }
    sz[1] = n;
    dfs3(1);
    cin >> q;
    vector<pair<int, int> > queries[1 + n];
    int ans[q];
    for(int i = 0; i < q; i++){
        int l, r;
        cin >> l >> r;
        queries[r].push_back(make_pair(l, i));
    }
    for(int i = 1; i <= n; i++){
        for(pair<int, int> x : values[i]){
            update(n - x.first + 1, x.second);
        }
		for(pair<int, int> x : queries[i]){
			if(x.first == i){
                ans[x.second]=-1;
            }
			else{
                ans[x.second] = query(n - x.first + 1);
            }
		}
	}
    for(int i = 0; i < q; i++){
        cout << ans[i] << "\n";
    }
}