/*
  Name: Asm.Def的基本算法
  Copyright: 
  Author: chairman
  Date: 08/10/16 17:04
  Description: 和简单的最近公共祖先类似，只是需要处处取模，计算一次取模一次，否则就炸 
*/
#include<iostream>
#include<cstdio>
using namespace std;
#define ll long long
int read()
{
	int x,f=1;
	char ch;
	while(ch=getchar(),!isdigit(ch))if(ch=='-')f=-1;
	x=ch-48;
	while(ch=getchar(),isdigit(ch))x=x*10+ch-48;
	return x*f;
}
void write(ll x)
{
	if(x<0)putchar('-'),x=-x;
	int cnt=0;char ch[50];
	while(ch[++cnt]=x%10+48,x/=10);
	while(putchar(ch[cnt]),--cnt);
	putchar('\n');
}
#define maxn 100100
struct edge
{
	int t,n;
}a[maxn];
int len,head[maxn],fa[maxn];
ll tot[maxn],val[maxn];
void insert(int x,int y)
{
	a[++len].t=y;a[len].n=head[x];head[x]=len;
}
ll ans=0;
#define k a[i].t
int mod=1000000007;
void dfs(int x)
{
	ans+=tot[x]*tot[x]%mod*tot[x]%mod;ans%=mod;
	ll tem=0;
	for(int i=head[x];i;i=a[i].n)
	{
		if(fa[x]==k)continue;
		dfs(k);
		tem+=tot[x]*tot[k]%mod*val[x]%mod;tem%=mod;
		tot[x]+=tot[k];tot[x]%=mod;
	}
	ans+=tem*2%mod;
	ans%=mod;
}
int main()
{
	freopen("asm_algo.in","r",stdin);
	freopen("asm_algo.out","w",stdout);
	int n=read();val[1]=tot[1]=read();
	for(int i=2;i<=n;i++)
	{
		int x=read();val[i]=tot[i]=read();
		fa[i]=x;
		insert(x,i);
	}
	dfs(1);
	write(ans);//while(1);
//	system("pause");
}