#include <bits/stdc++.h>
using namespace std;
#define rep(ii,aa,bb) for(re int ii = aa; ii <= bb; ii++)
#define Rep(ii,aa,bb) for(re int ii = aa; ii >= bb; ii--)
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef pair<int, ll> PII;
const int maxn = 2e5 + 5;
const ll inf = 1ll << 60;
namespace IO_ReadWrite {
	#define re register
	#define gg (p1 == p2 && (p2 = (p1 = _buf) + fread(_buf, 1, 1<<21, stdin), p1 == p2) ? EOF :*p1++)
	char _buf[1<<21], *p1 = _buf, *p2 = _buf;
	template <typename T>
	inline void read(T &x){
		x = 0; re T f=1; re char c = gg;
		while(c > 57 || c < 48){if(c == '-') f = -1;c = gg;}
		while(c >= 48 &&c <= 57){x = (x<<1) + (x<<3) + (c^48);c = gg;}
		x *= f;return;
	}
	inline void ReadChar(char &c){
		c = gg;
		while(!isalpha(c)) c = gg;
	}
	template <typename T>
	inline void write(T x){
		if(x < 0) putchar('-'), x = -x;
		if(x > 9) write(x/10);
		putchar('0' + x % 10);
	}
	template <typename T>
	inline void writeln(T x){write(x); putchar('\n');}
}
using namespace IO_ReadWrite;
int n, sz[maxn], rt, S, f[maxn], dis[maxn];
vector <PII> e[maxn], ds, d[maxn];
bool vis[maxn];
inline void findrt(int u, int fa) {
	sz[u] = 1, f[u] = 0;
	for(auto [v, w] : e[u]) {
		if(v == fa || vis[v]) continue;
		findrt(v, u);
		sz[u] += sz[v];
		f[u] = max(f[u], sz[v]);
	}
	f[u] = max(f[u], S - sz[u]);
	if(f[u] < f[rt]) rt = u;
}
inline void get_dis(int u, int fa) {
	ds.push_back({u, dis[u]});
	for(auto [v, w] : e[u]) {
		if(v == fa || vis[v]) continue;
		dis[v] = dis[u] + w;
		get_dis(v, u);
	}
}
int stk[maxn], top;
inline void calc(int u) {
	dis[u] = 0;
	ds.clear();
	get_dis(u, 0);
	sort(ds.begin(), ds.end());
	top = 0;
	for(auto [v, w] : ds) {
		while(top && w < dis[stk[top]]) top --;
		if(top) d[v].push_back({stk[top], w + dis[stk[top]]});
		stk[++ top] = v;
	}
	top = 0;
	reverse(ds.begin(), ds.end());
	for(auto [v, w] : ds) {
		while(top && w < dis[stk[top]]) top --;
		if(top) d[stk[top]].push_back({v, w + dis[stk[top]]});
		stk[++ top] = v;
	}
}
inline void solve(int u) {
	vis[u] = 1;
	calc(u);
	for(auto [v, w] : e[u]) {
		if(vis[v]) continue;
		S = sz[v], f[rt = 0] = n + 1;
		findrt(v, u);
		solve(rt);
	}
}
vector <PII> qry[1000005];
int q;
ll bit[maxn], ans[maxn];
inline int lowbit(int x) {return x & (-x);}
inline void upd(int x, ll v) {
	for(; x; x -= lowbit(x))
		bit[x] = min(bit[x], v);
}
inline ll qMin(int x) {
	ll res = inf;
	for(; x <= n; x += lowbit(x)) {
		res = min(res, bit[x]);
	}
	return res;
}
int main () {
	read(n);
	fill(bit, bit + n + 2, inf);
	rep(i, 1, n - 1) {
		int u, v, w;
		read(u); read(v); read(w);
		e[u].push_back({v, w});
		e[v].push_back({u, w});
	}
	S = n;
	f[rt = 0] = n + 1;
	findrt(1, 0);
	solve(rt);
	read(q);
	rep(i, 1, q) {
		int l, r;
		read(l); read(r);
		qry[r].push_back({l, i});
	}
	rep(r, 1, n) {
		for(auto [u, w] : d[r]) upd(u, w);
		for(auto [l, id] : qry[r]) {
			if(l == r) ans[id] = -1;
			else ans[id] = qMin(l);
		}
	}
	rep(i, 1, q) writeln(ans[i]);
	
	return 0;
}