#include using namespace std; using ll = long long; using P = pair; constexpr char newl = '\n'; struct LCA { using Graph = vector< vector >; const Graph& g; const int LOGV; const int root; vector< vector > parent; vector depth; LCA(const Graph& g, int root = 0) : g(g), LOGV(32 - __builtin_clz(g.size())), root(root) { int V = g.size(); parent.resize(LOGV, vector(V)); depth.resize(V); dfs(root, -1, 0); for (int k = 0; k + 1 < LOGV; k++) { for (int v = 0; v < V; v++) { if (parent[k][v] < 0) parent[k + 1][v] = -1; else parent[k + 1][v] = parent[k][parent[k][v]]; } } } void dfs(int v, int p, int d) { parent[0][v] = p; depth[v] = d; for (int i : g[v]) { if (i != p) dfs(i, v, d + 1); } } int operator()(int u, int v) const { if (depth[u] > depth[v]) swap(u, v); for (int k = 0; k < LOGV; k++) { if ((depth[v] - depth[u]) >> k & 1) { v = parent[k][v]; } } if (u == v) return u; for (int k = LOGV - 1; k >= 0; k--) { if (parent[k][u] != parent[k][v]) { u = parent[k][u]; v = parent[k][v]; } } return parent[0][u]; } }; using GraphW = vector< vector

>; void dfs(int cur, int par, const GraphW& g, vector& d) { for (const P& p : g[cur]) { if (p.first == par) continue; d[p.first] = d[cur] + p.second; dfs(p.first, cur, g, d); } } int main() { cin.tie(nullptr); ios::sync_with_stdio(false); int n; cin >> n; LCA::Graph g(n); GraphW g2(n); for (int i = 1; i < n; i++) { int a, b; ll c; cin >> a >> b >> c; --a; --b; g[a].push_back(b); g[b].push_back(a); g2[a].emplace_back(b, c); g2[b].emplace_back(a, c); } LCA lca(g); vector d(n, 0); dfs(0, -1, g2, d); int q; cin >> q; for (int i = 0; i < q; i++) { int s, t; cin >> s >> t; --s; --t; int l = lca(s, t); cout << d[s] + d[t] - d[l] * 2 << newl; } return 0; }