Codeforces Round 767C 树形结构求子树和

//Codeforces Round 767C
//树形结构,算子树总和 
#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6+6;
struct N{
	int v,nxt,w;
}node[maxn<<2];
int sum,num,cnt,head[maxn<<2]; 
int size[maxn],w[maxn];
int ans[3];
void add(int u,int v)
{
	++cnt;
	node[cnt].v = v;
	node[cnt].nxt= head[u];
	head[u] = cnt;
}
void dfs(int u,int fa){
	size[u] = w[u];
	for(int v,i=head[u];i;i=node[i].nxt){
			v = node[i].v;	
			if(v==fa)continue;
			dfs(v,u);
			size[u]+=size[v];
	}
	if(size[u]==sum)ans[++num]=u,size[u] = 0;
}
int main()
{
	int n,v,root;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d %d",&v,&w[i]);
		sum+=w[i];
		if(v==0){
			root = i; continue;
		}
		add(v,i);	add(i,v);
	}
	if(sum%3!=0){
		printf("-1\n");
	}else{
		sum/=3;
		dfs(root,0);
		if(num<=2){printf("-1\n");return 0;}
		printf("%d %d\n",ans[1],ans[2]);
	}
	
	return 0;
}