#include <iostream>

#include <cstdio>

#include <cmath>

#include <cstring>

#include <algorithm>

#include <vector>

using namespace std;

typedef long long LL;

const int N=1e6+,mod=,inf=2e9+;

int T,n,v[N],root,f,all,dp[N],si,first,second;

LL ans;

vector<int > G[N];

void dfs(int u,int fa) {

    dp[u] = v[u];

    for(int i = ; i < G[u].size(); ++i) {

        int to = G[u][i];

        if(to == fa) continue;

        dfs(to,u);

        dp[u] += dp[to];

    }

}

void dfs(int u) {

    if(dp[u] == all) {

        ans += first + second;

    }

    if(dp[u] == all* && u != root) second++;

    for(int i = ; i < G[u].size(); ++i) {

        int to = G[u][i];

        dfs(to);

    }

    if(dp[u] == all) first++;

    if(dp[u] == all* && u != root) second--;

}

int main() {

    scanf("%d",&T);

    while(T--) {

        scanf("%d",&n);

        for(int i = ; i <= n; ++i) G[i].clear();

        all = ;

        for(int i = ; i <= n; ++i) {

            scanf("%d%d",&v[i],&f);

            if(f == ) root = i;

            else G[f].push_back(i);

        }

        for(int i = ; i <= n; ++i) all += v[i];

        if((all % +)% != ) {

            puts("");

            continue;

        }

        all/=;si = ;ans = ;

        first = second = ;

        dfs(root,);

        dfs(root);

        printf("%lld\n",ans);

    }

    return ;

}