第2，第8个点WA（按照真实数据大小排列应该是第7和第10），答案偏大。

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=5e5+10;
int n,m;
int tot,head[N],ver[N<<1],nxt[N<<1],edge[N];
int dep[N],fa[N][22],len[N][22];
int army[N];
struct Move{
	int pl,lft;
}a[N],b[N];
int read(){
	int x=0,f=1;
	char ch=getchar();
	while(!isdigit(ch)){
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(isdigit(ch)){
		x=x*10+ch-'0';
		ch=getchar();
	}
	return x*f;
}
void add(int x,int y,int z){
	nxt[++tot]=head[x];
	head[x]=tot;
	ver[tot]=y;
	edge[tot]=z;
}
void dfs(int x){
	for(int i=1;i<=20;i++){
		fa[x][i]=fa[fa[x][i-1]][i-1];
		len[x][i]=len[x][i-1]+len[fa[x][i-1]][i-1];
	}
	for(int i=head[x];i;i=nxt[i]){
		int y=ver[i];
		int z=edge[i];
		if(y==fa[x][0])continue;
		fa[y][0]=x;
		len[y][0]=z;
		dfs(y);
	}
}
int stay[N];
void mark(int x,int fa){
	bool flag=true,son=false;
	for(int i=head[x];i;i=nxt[i]){
		int y=ver[i];
		if(y==fa)continue;
		mark(y,x);
		son=true;
		if(!stay[y])flag=false;
	}
	if(flag&&son)stay[x]++;
}
bool cmp1(Move x,Move y){
	return x.lft>y.lft;
}
bool cmp2(Move x,Move y){
	if(x.pl==y.pl)return x.lft>y.lft;
	return x.pl<y.pl;
}
int need[N];
int use[N];
bool cmp3(int x,int y){
	return x>y;
}
bool check(int maxtime){
	memcpy(b,a,sizeof b);
	memset(stay,0,sizeof stay);
	memset(need,0,sizeof need);
	memset(use,0,sizeof use);
	for(int i=1;i<=m;i++){
		b[i].lft=maxtime;
		for(int j=20;j>=0;j--){
			if(fa[b[i].pl][j]&&fa[b[i].pl][j]!=1&&len[b[i].pl][j]<=b[i].lft){
				b[i].lft-=len[b[i].pl][j];
				b[i].pl=fa[b[i].pl][j];
			}
		}
		stay[b[i].pl]++;
	}
	mark(1,0);
	sort(b+1,b+m+1,cmp1);
	for(int i=1;i<=m;i++){
		if(stay[b[i].pl]>1&&b[i].lft>=len[b[i].pl][0]){
			stay[b[i].pl]--;
			b[i].lft-=len[b[i].pl][0];
			b[i].pl=fa[b[i].pl][0];
		}
	}
	sort(b+1,b+m+1,cmp2);
	int cnt1=0,cnt2=0;
	for(int i=head[1];i;i=nxt[i]){
		int y=ver[i];
		if(!stay[y])need[++cnt1]=len[y][0];
	}
	sort(need+1,need+cnt1+1,cmp3);
	for(int i=1;i<=m;i++)if(b[i].pl==1)use[++cnt2]=b[i].lft;
	for(int i=1,j=1;i<=cnt1;i++,j++)if(use[j]<need[i])return false;
	return true;
}
signed main(){
	freopen("blockade10.in","r",stdin);
	n=read();
	for(int i=1;i<n;i++){
		int x=read(),y=read(),z=read();
		add(x,y,z);
		add(y,x,z);
	}
	dfs(1);
	m=read();
	for(int i=1;i<=m;i++)a[i].pl=read();
	int l=0,r=1e15,mid;
	while(l<r){
		mid=(l+r)>>1;
		if(check(mid))r=mid;
		else l=mid+1;
	}
	printf("%lld\n",r);
	return 0;
}