#include "bits/stdc++.h"
#include <x86intrin.h>
#include<ext/pb_ds/assoc_container.hpp>
#define MAXN 100009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace __gnu_pbds;
using namespace std;

typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
typedef tree<pair<ll,int>, null_type, less<pair<ll,int> >, rb_tree_tag, tree_order_statistics_node_update> tes;
const int offset=100001;
vector<int>adj[MAXN];
int med[MAXN],men[MAXN],sub[MAXN],vis[MAXN];
int sz[MAXN*2],multi;
tes s[MAXN*2];
ll ans=0;
void pre(int nd,int pr){
	sub[nd]=1;
	tr(it,adj[nd])
		if(*it!=pr and !vis[*it]){
			pre(*it,nd);
			sub[nd]+=sub[*it];
		}
}
int dfs1(int nd,int pr,int sz){
	tr(it,adj[nd])
		if(*it!=pr and !vis[*it] and sub[*it]>sz)
			return dfs1(*it,nd,sz);
	return nd;
}
int tap(int x,ll y){
	int res=0;
	for(;x<=200001;x+=x&(-x)){
		if(!sz[x])
			continue;
		int val=sz[x]-s[x].order_of_key(mp(y,0));
		res+=val;
	}
	return res;
}
void get(int nd,int pr,int X,ll Y){
	X+=med[nd];Y+=men[nd];
	ans+=(X>=0 and Y>=0);
	ans+=tap(-X+offset,-Y);
	tr(it,adj[nd])
		if(*it!=pr and !vis[*it])
			get(*it,nd,X,Y);
}
stack<pair<int,pair<ll,int> > >st;
void update(int x,ll y,int turn,int id){
	for(;x;x-=x&(-x)){
		if(turn)
			s[x].insert(mp(y,id)),sz[x]++;
		else
			s[x].erase(mp(y,id)),sz[x]--;
	}
}
void upd(int nd,int pr,int X,ll Y){
	X+=med[nd];Y+=men[nd];
	++multi;
	update(X+offset,Y,1,multi);
	st.push(mp(X+offset,mp(Y,multi)));
	tr(it,adj[nd])
		if(*it!=pr and !vis[*it])
			upd(*it,nd,X,Y);
}
void solve(int nd){
	ans+=(med[nd]>=0 and men[nd]>=0);
	for(int i=0;i<int(adj[nd].size());i++){
		int to=adj[nd][i];
		if(vis[to])
			continue;
		get(to,-1,med[nd],men[nd]);
		upd(to,-1,0,0);
	}
	while(!st.empty()){
		int xx=st.top().ff;
		ll yy=st.top().ss.ff;
		int mm=st.top().ss.ss;
		st.pop();
		update(xx,yy,0,mm);
	}multi=0;
}
void dfs(int nd){
	pre(nd,-1);
	int centr=dfs1(nd,-1,sub[nd]>>1);
	vis[centr]=1;solve(centr);
	tr(it,adj[centr])
		if(!vis[*it])
			dfs(*it);
}
int main(){

	srand(__rdtsc());
    //~ freopen("file.in", "r", stdin);
    int t=2;
    //~ scanf("%d",&t);
    while(t--){
		int n=100000,X=rand()%1000000000,Y=rand()%1000000000;
		//~ scanf("%d%d%d",&n,&X,&Y);
		for(int i=1;i<=n;i++){
			int x=rand()%1000000000;
			//~ scanf("%d",&x);
			med[i]=(x<=X)*2-1;
			men[i]=x-Y;
		}
		for(int i=2;i<=n;i++){
			int u=rand()%(i-1)+1,v=i;
			//~ scanf("%d%d",&u,&v);
			adj[u].pb(v);
			adj[v].pb(u);
		}dfs(1);
		printf("%lld\n",ans);
		for(int i=1;i<=n;i++)
			vis[i]=0,adj[i].clear();
		ans=0;
	}
	return 0;
}