//Shirasu Azusa 2024.02.19
#include <bits/stdc++.h>
#define fi first
#define se second
#define eb emplace_back
#define mp make_pair
using namespace std;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128;
template<typename T,typename U>
T ceil(T x, U y) {return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>
T floor(T x, U y) {return (x>0?x/y:(x-y+1)/y);}
template<class T,class S>
bool chmax(T &a,const S b) {return (a<b?a=b,1:0);}
template<class T,class S>
bool chmin(T &a,const S b) {return (a>b?a=b,1:0);}
int popcnt(int x) {return __builtin_popcount(x);}
int popcnt(ll x)  {return __builtin_popcountll(x);}
int topbit(int x) {return (x==0?-1:31-__builtin_clz(x));}
int topbit(ll x)  {return (x==0?-1:63-__builtin_clzll(x));}
int lowbit(int x) {return (x==0?-1:__builtin_ctz(x));}
int lowbit(ll x)  {return (x==0?-1:__builtin_ctzll(x));}

#define int long long
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vp;
typedef tuple<int,int,int> tiii;
int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();} 
  return x*w;
}

const int N=2e5+5,inf=0x3f3f3f3f3f3f3f3f;
int n,q,ql[N],id[N],ans[N],sz[N],rt,rsz,vst[N],d[N],msz[N];
vp e[N],g[N]; vi p,t[N];

void dfs1(int u,int fa) {
  sz[u]=1; msz[u]=0;
  for(auto [v,w]:e[u]) if(v!=fa&&!vst[v]) {
    dfs1(v,u); sz[u]+=sz[v];
    chmax(msz[u],sz[v]);
  } chmax(msz[u],sz[0]-sz[u]);
  if(chmin(rsz,msz[u])) rt=u;
}
void dfs2(int u,int fa) {
  p.eb(u); sz[u]=1;
  for(auto [v,w]:e[u]) if(v!=fa&&!vst[v]) {
    d[v]=d[u]+w; dfs2(v,u); sz[u]+=sz[v];
  }
}
void dfs3(int u) {
  //cout<<"DD "<<u<<endl;
  sz[0]=sz[u]; rsz=n+1; dfs1(u,0);
  d[rt]=0; p.clear(); dfs2(rt,0);
  sort(p.begin(),p.end());
  static int st[N]; int top=0;
  //cout<<" rt="<<rt<<endl;
  //for(int x:p) cout<<x<<" "; puts("");
  for(int x:p) {
    while(top&&d[st[top]]>d[x]) --top;
    if(top) g[x].eb(st[top],d[x]+d[st[top]]);
    st[++top]=x;
  }
  reverse(p.begin(),p.end()); top=0;
  for(int x:p) {
    while(top&&d[st[top]]>d[x]) --top;
    if(top) g[st[top]].eb(x,d[x]+d[st[top]]);
    st[++top]=x;
  }
  vst[rt]=1;
  for(auto [v,w]:e[rt]) if(!vst[v]) dfs3(v);
}

int s[N];
void clear() {rep(i,0,n+1) s[i]=inf;}
void add(int x,int y) {for(;x;x-=x&-x) chmin(s[x],y);}
int qry(int x,int y=inf) {for(;x<=n;x+=x&-x) chmin(y,s[x]); return y;}

signed main() {
  n=read();
  rep(i,2,n) {
    int u=read(), v=read(), w=read();
    e[u].eb(v,w), e[v].eb(u,w);
  }
  sz[1]=n; dfs3(1);
  q=read();
  rep(i,1,q) {
    ql[i]=read(); int qr=read();
    t[qr].eb(i);
  } clear();
  rep(i,1,n) {
    for(auto [l,w]:g[i]) add(l,w);
    for(int x:t[i]) ans[x]=qry(ql[x]);
  }
  rep(i,1,q) {
    if(ans[i]==inf) puts("-1");
    else printf("%lld\n",ans[i]);
  }
  return 0;
}