#include <bits/stdc++.h>
#define il inline
#define pii pair<int,int>
#define fi first
#define se second
using namespace std;
typedef long long ll;
il int read(){
    int x=0,c=getchar(),f=0;
    while(!isdigit(c)) f|=c=='-',c=getchar();
    while(isdigit(c)) x=x*10+c-48,c=getchar();
    return f?-x:x;
}
const int N=5e5+5,M=1e6+5,K=2e7+5;const ll inf=1e18;
int n,q,fa[N],de[N],SIZ[N],dfn[N],top[N],son[N];ll s[N];
int vis[N],siz[N],mx[N],rt,tot;ll d[N],ans[M];
vector<pii> e[N],g[N];
il void add(int x,int y,int z){e[x].push_back({y,z});}
struct node{
    int u,v;ll w;
    il node(){u=v=0,w=0ll;}
    il node(int u,int v,ll w) : u(u),v(v),w(w) {}
    bool operator<(const node &x) const {return v<x.v;}
}f[K];int k;
void DFS(int x,int fath){
    int y,z;fa[x]=fath,de[x]=de[fath]+1,SIZ[x]=1;
    for(auto it:e[x]){
        y=it.fi,z=it.se;if(y==fath) continue;
        s[y]=s[x]+1ll*z,DFS(y,x),SIZ[x]+=SIZ[y];
        if(SIZ[y]>SIZ[son[x]]) son[x]=y;
    }
}
void DFS1(int x,int t){
    top[x]=t;
    if(son[x]) DFS1(son[x],t);
    for(auto it:e[x]) if(it.fi!=fa[x] && it.fi!=son[x]) DFS1(it.fi,it.fi);
}
il int lca(int x,int y){
    while(top[x]!=top[y]){
        if(de[top[x]]<de[top[y]]) swap(x,y);
        x=fa[top[x]];
    }return de[x]<de[y]?x:y;
}
il ll dis(int x,int y){return s[x]+s[y]-2ll*s[lca(x,y)];}
void dfs0(int x,int fath){
    ++tot;
    for(auto it:e[x])if(it.fi!=fath && !vis[it.fi]) dfs0(it.fi,x);
}
void dfs(int x,int fath){
    int y;siz[x]=1,mx[x]=0;
    for(auto it:e[x]){
        y=it.fi;if(y==fath || vis[y]) continue;
        dfs(y,x),siz[x]+=siz[y],mx[x]=max(mx[x],siz[y]);
    }mx[x]=max(mx[x],tot-siz[x]);
    if(!rt || mx[x]<mx[rt]) rt=x;
}
int m,a[N],st[N],TOP;
void dfs1(int x,int fath){
    int y,z;a[++m]=x;
    for(auto it:e[x]){
        y=it.fi,z=it.se;if(y==fath || vis[y]) continue;
        d[y]=d[x]+1ll*z,dfs1(y,x);
    }
}
il void calc(int x){
    int y,z,u,v,w,p;m=0,d[x]=0ll;
    dfs1(x,0);sort(a+1,a+1+m);
    TOP=0;
    for(int i=1;i<=m;++i){
        while(TOP && d[st[TOP]]>=d[a[i]]) f[++k]={st[TOP],a[i],d[st[TOP]]+d[a[i]]},--TOP;
        st[++TOP]=a[i];
    }TOP=0;
    for(int i=m;i;--i){
        while(TOP && d[st[TOP]]>=d[a[i]]) f[++k]={a[i],st[TOP],d[st[TOP]]+d[a[i]]},--TOP;
        st[++TOP]=a[i];
    }TOP=0;
}
void solve(int x){
    int y;vis[x]=1,calc(x);
    for(auto it:e[x]){
        y=it.fi;if(vis[y]) continue;
        rt=tot=0,dfs0(y,x),dfs(y,x),solve(rt);
    }
}
ll t[N<<2];
il void pushup(ll x){t[x]=min(t[x<<1],t[x<<1|1]);}
void build(int x,int l,int r){
    t[x]=inf;if(l==r) return ;
    int mid=(l+r)>>1;
    build(x<<1,l,mid),build(x<<1|1,mid+1,r);
    pushup(x);
}
void update(int x,int l,int r,int p,ll v){
    if(l==r){t[x]=min(t[x],v);return ;}
    int mid=(l+r)>>1;
    if(p<=mid) update(x<<1,l,mid,p,v);
    else update(x<<1|1,mid+1,r,p,v);
    pushup(x);
}
ll query(int x,int l,int r,int L,int R){
    if(l>=L && r<=R) return t[x];
    int mid=(l+r)>>1;
    if(L>mid) return query(x<<1|1,mid+1,r,L,R);
    else if(R<=mid) return query(x<<1,l,mid,L,R);
    else return min(query(x<<1,l,mid,L,R),query(x<<1|1,mid+1,r,L,R));
}
int x,y,z,p;
int main(){
    scanf("%d",&n);
    for(int i=1;i<n;++i) x=read(),y=read(),z=read(),add(x,y,z),add(y,x,z);
    scanf("%d",&q);
    for(int i=1;i<=q;++i) x=read(),y=read(),g[y].push_back({x,i});
    DFS(1,0),DFS1(1,1),build(1,1,n);
    rt=0,tot=n,dfs(1,0),solve(rt);
    sort(f+1,f+1+k);
    for(int i=1;i<=k;++i){
        if(f[i].u>f[i].v) while(1);
        if(dis(f[i].u,f[i].v)>f[i].w) while(1);
        //f[i].w=dis(f[i].u,f[i].v);
    }
    //for(int i=1;i<=k;++i) printf("*** %d %d %lld\n",f[i].u,f[i].v,f[i].w);
    for(int i=1;i<=n;++i){
        //for(auto it:f[i]) update(1,1,n,it.fi,it.se);
        while(p<k && f[p+1].v<=i) ++p,update(1,1,n,f[p+1].u,f[p+1].w);
        for(auto it:g[i]) {
            if(it.fi==i) ans[it.se]=-1;
            else ans[it.se]=query(1,1,n,it.fi,i-1);
        }
    }
    for(int i=1;i<=q;++i) printf("%lld\n",ans[i]);
    return 0;
}