#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <vector>
#include <iomanip>
#define ALL(x) (x).begin(), (x).end()
#define rt return
#define dll(x) scanf("%I64d",&x)
#define xll(x) printf("%I64d\n",x)
#define sz(a) int(a.size())
#define all(a) a.begin(), a.end()
#define rep(i,x,n) for(int i=x;i<n;i++)
#define repd(i,x,n) for(int i=x;i<=n;i++)
#define pii pair<int,int>
#define pll pair<long long ,long long>
#define gbtb ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define MS0(X) memset((X), 0, sizeof((X)))
#define MSC0(X) memset((X), '\0', sizeof((X)))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define eps 1e-6
#define gg(x) getInt(&x)
#define db(x) cout<<"== [ "<<x<<" ] =="<<endl;
using namespace std;
typedef long long ll;
ll gcd(ll a, ll b) {return b ? gcd(b, a % b) : a;}
ll lcm(ll a, ll b) {return a / gcd(a, b) * b;}
ll powmod(ll a, ll b, ll MOD) {ll ans = 1; while (b) {if (b % 2)ans = ans * a % MOD; a = a * a % MOD; b /= 2;} return ans;}
inline void getInt(int* p);
const int maxn = 100010;
const int inf = 0x3f3f3f3f;
/*** TEMPLATE CODE * * STARTS HERE ***/
int n;
struct node
{int next;ll x;
};
ll ans = 0ll;
std::vector<node> son[maxn];
const ll mod = 1e9 + 7;
ll num[maxn];
void dfs_num(int x)
{// num[x] 代表x的子树的节点个数。//
    num[x]++;for (auto y : son[x]){dfs_num(y.next);num[x] += num[y.next];}
}
map<ll, int> m;
ll tmp = 0ll;
void dfs1(int id, ll s)
{// 同一条链ans = (ans + 1ll * num[id] * m[s]) % mod;for (auto y : son[id]){tmp = (tmp + 1ll * num[id] - num[y.next]) % mod;m[s] = (m[s] + tmp) % mod;dfs1(y.next, s ^ y.x);m[s] -= tmp;m[s] = (m[s] + mod) % mod;tmp -= 1ll * num[id] - num[y.next];tmp = (tmp + mod) % mod;}
}
void dfs2(int id, ll s)
{// 不同链ans = (ans + 1ll * num[id] * m[s]) % mod;for (auto y : son[id]){dfs2(y.next, s ^ y.x);}m[s] = (m[s] + num[id]) % mod;
}
int main()
{// freopen("D:\\common_text\\code_stream\\in.txt","r",stdin);//freopen("D:\\common_text\\code_stream\\out.txt","w",stdout);
    gbtb;cin >> n;int id; ll x; node temp;repd(i, 2, n){cin >> id;cin >> x;temp.x = x;temp.next = i;son[id].push_back(temp);}dfs_num(1);// db(ans);dfs1(1, 0ll);m.clear();dfs2(1, 0ll);cout << (ans + mod) % mod;return 0;
}inline void getInt(int* p) {char ch;do {ch = getchar();} while (ch == ' ' || ch == '\n');if (ch == '-') {*p = -(getchar() - '0');while ((ch = getchar()) >= '0' && ch <= '9') {*p = *p * 10 - ch + '0';}}else {*p = ch - '0';while ((ch = getchar()) >= '0' && ch <= '9') {*p = *p * 10 + ch - '0';}}
}