#include<algorithm>
#include<iostream>
#include<cstring>
#include<vector>
#include<cmath>
#define pb push_back
using ll = long long;
const int N = 5e5 + 10, M = 2e6 + 10;
std::vector<std::pair<int, int>> g[N], q[N];
int n, m, nn, rt, t, md, ms[N], sz[N], vs[N]; ll rs[N];
std::pair<int, ll> a[N]; int tp, st[N]; std::vector<int> vc[N];
namespace dis{
    ll D[N]; int d[N], c, f[20][N<<1], p[N];
    void pr(int x, int fa){
        d[x]=d[fa]+1,++c,p[x]=c,f[0][c]=x;
        for(auto [v,w]:g[x]) if(v!=fa){
            D[v] = D[x] + w;
            pr(v, x), f[0][++c] = x;
        }
    }
    void bd(){
        pr(1, 0); for(int i = 1; 1 << i <= c; i++)
                for(int j = 1; j <= c + 1 - (1 << i); j++)
        f[i][j]=d[f[i-1][j]]<d[f[i-1][j+(1<<i-1)]]?f[i-1][j]:f[i-1][j+(1<<i-1)];
    }
    int lca(int x, int y){
        if((x=p[x])>(y=p[y])) std::swap(x, y); int k=std::__lg(y-x+1);
        return d[f[k][x]]<d[f[k][y-(1<<k)+1]]?f[k][x]:f[k][y+1-(1<<k)];
    }
    ll ds(int x, int y){return D[x]+D[y]-2ll*D[lca(x,y)];}
} using dis::ds;
struct bt{
    ll t[N]; bt(){memset(t, 63, sizeof t);}
    void upd(int p,ll x){for(;p;p-=p&-p)t[p]=std::min(t[p],x);}
    ll qmi(int p){ll r=9e18;for(;p<=n;p+=p&-p)r=std::min(r,t[p]);return r;}
}T;
void fd(int x, int fa){
    sz[x] = 1, ms[x] = 0;
    for(auto [v,w]:g[x]) if(!vs[v]&&v!=fa){
        fd(v, x), sz[x] += sz[v];
        ms[x] = std::max(ms[x], sz[v]);
    } if((ms[x]=std::max(ms[x],nn-sz[x]))<md) md=ms[x],rt=x;
}
void gd(int x, int fa, ll d){
    a[++t] = {x, d};
    for(auto [v, w] : g[x]) 
        if(v != fa && !vs[v]) gd(v, x, d+w);
}
void sol(int x){
    vs[x] = 1; t = 0; gd(x, 0, 0);
    std::sort(a + 1, a + t + 1);
    tp = 0; for(int i = 1; i <= t; i++){
        while(tp&&a[st[tp]].second>a[i].second)tp--;
        if(tp) vc[a[i].first].pb(a[st[tp]].first); st[++tp] = i;
    } tp = 0; for(int i = t; i; i--){
        while(tp&&a[st[tp]].second>a[i].second)tp--;
        if(tp) vc[a[st[tp]].first].pb(a[i].first); st[++tp] = i;
    } for(auto [v,w]:g[x]) if(!vs[v])
        rt = 0, md = n, nn = sz[v], fd(v, x), sol(rt);
}
int main(){
    // freopen("in", "r", stdin);
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);std::cout.tie(0);
    std::cin >> n; for(int i = 1, u, v, w; i < n; i++)
        std::cin >> u >> v >> w, g[u].pb({v, w}), g[v].pb({u, w});
    std::cin >> m; for(int i = 1, l, r; i <= m; i++)
        std::cin >> l >> r, l >= r ? rs[i] = -1, void() : q[r].pb({l, i});
    dis::bd(); rt=0, md=n, nn=n; fd(1, 0), sol(rt);
    for(int i = 1; i <= n; i++){
        for(int j:vc[i]) T.upd(j, ds(i, j));
        for(auto [l,p]:q[i]) rs[p] = T.qmi(l);
    } for(int i = 1; i <= m; i++) std::cout << rs[i] << '\n';
}