#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; //#define int long long typedef long long ll; typedef unsigned long long ul; typedef unsigned int ui; constexpr ll mod = 1000000007; const ll INF = mod * mod; typedef pairP; #define stop char nyaa;cin>>nyaa; #define rep(i,n) for(int i=0;i=0;i--) #define Rep(i,sta,n) for(int i=sta;i=1;i--) #define Rep1(i,sta,n) for(int i=sta;i<=n;i++) #define all(v) (v).begin(),(v).end() typedef pair LP; typedef long double ld; typedef pair LDP; const ld eps = 1e-12; const ld pi = acosl(-1.0); ll mod_pow(ll x, ll n, ll m = mod) { ll res = 1; while (n) { if (n & 1)res = res * x % m; x = x * x % m; n >>= 1; } return res; } struct modint { ll n; modint() :n(0) { ; } modint(ll m) :n(m) { if (n >= mod)n %= mod; else if (n < 0)n = (n % mod + mod) % mod; } operator int() { return n; } }; bool operator==(modint a, modint b) { return a.n == b.n; } modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; } modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; } modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; } modint operator+(modint a, modint b) { return a += b; } modint operator-(modint a, modint b) { return a -= b; } modint operator*(modint a, modint b) { return a *= b; } modint operator^(modint a, ll n) { if (n == 0)return modint(1); modint res = (a * a) ^ (n / 2); if (n % 2)res = res * a; return res; } ll inv(ll a, ll p) { return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p); } modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); } const int max_n = 1 << 19; modint fact[max_n], factinv[max_n]; void init_f() { fact[0] = modint(1); for (int i = 0; i < max_n - 1; i++) { fact[i + 1] = fact[i] * modint(i + 1); } factinv[max_n - 1] = modint(1) / fact[max_n - 1]; for (int i = max_n - 2; i >= 0; i--) { factinv[i] = factinv[i + 1] * modint(i + 1); } } modint comb(int a, int b) { if (a < 0 || b < 0 || a < b)return 0; return fact[a] * factinv[b] * factinv[a - b]; } int gcd(int a, int b) { if (a < b)swap(a, b); while (b) { int r = a % b; a = b; b = r; } return a; } int depth[1 << 17]; int par[1 << 17][17]; ll parcost[1 << 17][17]; int specost[1 << 17][17]; vector costs[1 << 17]; vector ids[1 << 17]; multiset st[1 << 17]; struct edge { int to, cost; }; bool operator<(const edge& a, const edge& b) { if (a.to != b.to)return a.to < b.to; return a.cost < b.cost; } int lca(int a, int b) { if (depth[a] > depth[b])swap(a, b); //cout << "bef " << a << " " << b << "\n"; int dif = depth[b] - depth[a]; //cout << dif << "\n"; rep(j, 17)if (dif & (1 << j)) { b = par[b][j]; } //cout << "aft " << a << " " << b << "\n"; if (a == b)return a; else { per(j, 17) { if (par[a][j] != par[b][j]) { a = par[a][j], b = par[b][j]; } } return par[a][0]; } } int calcspe(int x, int d) { int res = mod; rep(j, 17) { if (d & (1 << j)) { res = min(res, specost[x][j]); x = par[x][j]; } } return res; } int calcloc(int x, int d) { rep(j, 17) { if (d & (1 << j)) { x = par[x][j]; } } return x; } ll calcsum(int x, int d) { ll res = 0; rep(j, 17) { if (d & (1 << j)) { res += parcost[x][j]; x = par[x][j]; } } return res; } void solve() { int n; cin >> n; vector> G(n); rep(i, n - 1) { int a, b, c; cin >> a >> b >> c; a--; b--; G[a].push_back({ b,c }); G[b].push_back({ a,c }); } rep(i, n)sort(all(G[i])); function dfs = [&](int id, int fr) { par[id][0] = fr; for (edge e : G[id])if (e.to != fr) { parcost[e.to][0] = e.cost; depth[e.to] = depth[id] + 1; dfs(e.to, id); costs[id].push_back(e.cost); ids[id].push_back(e.to); st[id].insert(e.cost); } st[id].insert(mod); for (edge e : G[id])if (e.to != fr) { auto itr = st[id].begin(); if ((*st[id].begin()) == e.cost)itr++; specost[e.to][0] = (*itr); } }; dfs(0, -1); rep(j, 16)rep(i, n) { if (par[i][j] >= 0) { par[i][j + 1] = par[par[i][j]][j]; parcost[i][j + 1] =parcost[i][j]+parcost[par[i][j]][j]; specost[i][j + 1] = min(specost[i][j], specost[par[i][j]][j]); } else { par[i][j + 1] = -1; } } int q; cin >> q; rep(i, q) { int x, y; cin >> x >> y; x--; y--; int l = lca(x, y); //cout << "ai " << l << "\n"; int mi = mod; if (depth[x]-depth[l]>1) { mi = min(mi, calcspe(x, depth[x] - depth[l] - 2)); } if (depth[y]-depth[l]>1) { mi = min(mi, calcspe(y, depth[y] - depth[l] - 2)); } if (y == l)swap(x, y); if (x == l) { int py = calcloc(y, depth[y] - depth[l] - 1); py = lower_bound(all(ids[l]), py) - ids[l].begin(); int val = costs[l][py]; auto itr = st[l].begin(); if (*itr == val)itr++; mi = min(mi, *itr); mi = min(mi, *st[y].begin()); } else { mi = min(mi, *st[x].begin()); mi = min(mi, *st[y].begin()); int px = calcloc(x, depth[x] - depth[l] - 1); int py = calcloc(y, depth[y] - depth[l] - 1); px = lower_bound(all(ids[l]), px) - ids[l].begin(); py = lower_bound(all(ids[l]), py) - ids[l].begin(); int val[2] = { costs[l][px],costs[l][py] }; if (val[0] > val[1])swap(val[0], val[1]); auto itr = st[l].begin(); rep(aa, 2) { if (*itr == val[aa]) { itr++; } else break; } mi = min(mi, (*itr)); } if (par[l][0] >= 0) { mi = min(mi, (int)parcost[l][0]); } if (mi == mod) { cout << -1 << "\n"; } else { //cout << mi<<" hoge\n"; ll ans = 2*mi; ans += calcsum(x, depth[x] - depth[l]); //cout << x << " " << depth[x] - depth[l] << " " << calcsum(x,depth[x] - depth[l])<<"\n"; ans += calcsum(y, depth[y] - depth[l]); cout << ans << "\n"; } } } signed main() { ios::sync_with_stdio(false); cin.tie(0); //cout << fixed << setprecision(15); //init_f(); //init(); //expr(); //int t; cin >> t; rep(i, t) solve(); return 0; }