#include using namespace std; #define rep(i, n) for(int i = 0; i < (int)n; ++i) #define FOR(i, a, b) for(int i = a; i < (int)b; ++i) #define rrep(i, n) for(int i = ((int)n - 1); i >= 0; --i) using ll = long long; using ld = long double; const ll INF = 1e18; const int Inf = 1e9; const double EPS = 1e-9; const int MOD = 1e9 + 7; template class LCA { public: int n, log_v = 0; vector depth; vector costs; vector > to; vector > cost; vector > parent; LCA() {} LCA(int n_): n(n_) { while ((1 << log_v) < n) ++log_v; depth.assign(n, 0); costs.assign(n, 0); to = vector >(n); cost = vector >(n); parent = vector >(log_v, vector(n, 0)); } void init(int root = 0) { dfs(root); rep (i, log_v - 1) { rep (j, n) parent[i + 1][j] = parent[i][parent[i][j]]; } } void addEdge(int u, int v, T c = 0) { to[u].push_back(v); to[v].push_back(u); cost[u].push_back(c); cost[v].push_back(c); } void dfs(int v, int p = -1, int d = 0, T c = 0) { if (p != -1) parent[0][v] = p; depth[v] = d; costs[v] = c; rep (i, to[v].size()) { int e = to[v][i]; if (e == p) continue; dfs(e, v, d + 1, c + cost[v][i]); } } int query(int u, int v) { if (depth[u] > depth[v]) swap(u, v); rep (i, log_v) { if ((depth[v] - depth[u]) >> i & 1) v = parent[i][v]; } if (u == v) return u; for (int i = log_v - 1; i >= 0; --i) { if (parent[i][u] != parent[i][v]) { u = parent[i][u]; v = parent[i][v]; } } return parent[0][u]; } int length(int u, int v) { return depth[u] + depth[v] - 2 * depth[query(u, v)]; } T dist(int u, int v) { return costs[u] + costs[v] - 2 * costs[query(u, v)]; } // is x on the path u - v bool isOnPath(int u, int v, int x) { return length(u, x) + length(v, x) == length(u, v); } }; int main() { cin.tie(nullptr); ios::sync_with_stdio(0); int n, q; cin >> n; LCA lca = LCA(n); rep (i, n - 1) { int a, b, c; cin >> a >> b >> c; lca.addEdge(a - 1, b - 1, c); } lca.init(); cin >> q; rep (i, q) { int s, t; cin >> s >> t; cout << lca.dist(s - 1, t - 1) << endl; } return 0; }