#pragma GCC optimize(3,"Ofast","inline")
#include <bits/stdc++.h>

using namespace std;

#define lep(i, l, r) for(int i = (l); i <= (r); i ++)
#define rep(i, l, r) for(int i = (l); i >= (r); i --)
#define Lep(i, l, r) for(int i = (l); i <  (r); i ++)
//#define debug(...) fprintf (stderr, __VA_ARGS__)
#define debug(...) 

using i64 = long long;
using ld = long double;
using LL = long long;
using ui64 = unsigned long long;
using ull = unsigned long long;

const int P = 998244353;
inline int mod(int x) { return x + (x >> 31 & P); }
inline void pls(int &x, int y) { x = mod(x + y - P); }
inline void sub(int &x, int y) { x = mod(x - y); }
inline int  add(int x, int y) { return mod (x + y - P); }
inline int  dec(int x, int y) { return mod (x - y); }
template <typename T> inline void ckmin(T &x, T y) { if (x > y) x = y; }
template <typename T> inline void ckmax(T &x, T y) { if (x < y) x = y; }

inline int power(int x, int k) {
	int res = 1;
	while(k) {
		if (k & 1) res = 1ll * res * x % P;
		x = 1ll * x * x % P; k >>= 1;
	} return res;
}

const int N = 2e5 + 5;

int n;
vector<pair<int, int> > e[N];
vector<pair<int, i64> > lnk[N];
vector<pair<int, int> > qry[N * 5];
i64 ans[N * 5];

int sz[N], rt = 1, all, vis[N];
void findroot(int x, int fx) {
	sz[x] = 1;
	int mx = 0;
	for (auto [y, w] : e[x]) if (y != fx && ! vis[y]) {
		findroot(y, x);
		sz[x] += sz[y];
		ckmax(mx, sz[y]);
	}
	ckmax(mx, all - sz[x]);
	if (mx * 2 <= all) rt = x;
}

void calc(int x) {
	vector<pair<int, i64> > dis;
	function<void(int, int, i64)> dfs = [&](int x, int fa, i64 curd) {
		dis.emplace_back (x, curd);
		for (auto [y, w] : e[x]) if (y != fa && ! vis[y]) {
			dfs (y, x, curd + w);
		}
	};
	dfs (x, 0, 0);
	sort (dis.begin(), dis.end());

	static int stk[N];
	int top = 0;
	for (int i = 0; i < dis.size(); i ++) {
		auto [v, w] = dis[i];
		while (top && dis[stk[top]].second > w) -- top;
		if (top) {
			lnk[v].emplace_back (dis[stk[top]].first, w + dis[stk[top]].second);
		}
		stk[++ top] = i;
	}
	
	top = 0;
	for (int i = dis.size() - 1; i >= 0; i --) {
		auto [v, w] = dis[i];
		while (top && dis[stk[top]].second > w) -- top;
		if (top) {
			lnk[dis[stk[top]].first].emplace_back (v, w + dis[stk[top]].second);
		}
		stk[++ top] = i;
	}
}

void Solve(int x) {
	calc (x);
	vis[x] = 1;
	for (auto [y, w] : e[x]) if (! vis[y]) {
		all = sz[y];
		findroot(y, x);
		Solve(rt);
	}
}

#define lowbit(x) (x & -x)
i64 c[N];
void upd (int x, i64 y) {
	for (; x; x -= lowbit(x)) ckmin(c[x], y);
}
i64 ask (int x) {
	i64 res = 1e18 + 5;
	for (; x <= n; x += lowbit(x)) ckmin (res, c[x]);
	return res;
}

void solve() {
	cin >> n;
	lep (i, 1, n) c[i] = 1e18 + 5;
	lep (i, 2, n) {
		int x, y, w;
		cin >> x >> y >> w;
		e[x].push_back ( {y, w} );
		e[y].push_back ( {x, w} );
	}
	rt = 1;
	all = n;
	findroot (1, 0);
	findroot (rt, 0);
	Solve (rt);

	int q;
	cin >> q;
	lep (i, 1, q) {
		int l, r;
		cin >> l >> r;
		qry[r].push_back ( {l, i} );
	}

	lep (r, 1, n) {
		for (auto [pos, w] : lnk[r]) {
			upd (pos, w);
			//cerr << pos << ' ' << r << ' ' << w << endl;
		}
		for (auto [l, id] : qry[r]) {
			ans[id] = ask (l);
		}
	}

	lep (i, 1, q) if (ans[i] > 1e16) ans[i] = - 1;
	lep (i, 1, q) cout << ans[i] << '\n';

	lep (i, 1, n) e[i].clear();
	lep (i, 1, n) lnk[i].clear();
	lep (i, 1, q) qry[i].clear();
	lep (i, 1, n) vis[i] = 0;
}

signed main() {
	ios :: sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int Case = 1;
	while (Case --) solve();
	return 0;
}