C++ :

#include <bits/stdc++.h>
using namespace std;

struct nod{
	int l, r, w;
};

nod tree[1000010], tree1[1000010];
int n, cnt[1000010], ans = 0;

void read(int &x){ 
	int f=1;x=0;char s=getchar();
	while(s<'0'||s>'9'){if (s=='-')f=-1;s=getchar();}
	while(s>='0'&&s<='9') {x=x*10+s-'0';s=getchar();}
	x*=f;
}

void readp(){
	read(n);
	for (int i = 1; i <= n; ++i){
		read(tree[i].w);
		tree1[i].w = tree[i].w;
	}
	for (int i = 1; i <= n; ++i){
		read(tree[i].l);
		read(tree[i].r);
		tree1[i].r = tree[i].l;
		tree1[i].l = tree[i].r;
	}
}

int dfs(int root){
	int s = 1;  
	if (tree[root].l != -1) 
		s += dfs(tree[root].l);
	if (tree[root].r != -1)  
		s += dfs(tree[root].r);
	return cnt[root] = s;
}

bool check(int r1, int r2){
	if (tree[r1].w != tree1[r2].w)
		return false;
	bool f1, f2;
	if (tree[r1].l == -1 && tree1[r2].l == -1)
		f1 = true;
	else if (tree[r1].l != -1 && tree1[r2].l != -1)
		f1 = check(tree[r1].l, tree1[r2].l);
	else
		f1 = false;
	if (tree[r1].r == -1 && tree1[r2].r == -1)
		f2 = true;
	else if (tree[r1].r != -1 && tree1[r2].r != -1)
		f2 = check(tree[r1].r, tree1[r2].r);
	else
		f2 = false;
	return f1 && f2;
}

int main(){
	readp();
	memset(cnt, -1, sizeof(cnt));
	dfs(1);
	for (int i = 1; i <= n; ++i){
		if (cnt[i] <= ans)
			continue;
		if (check(i, i))
			ans = max(ans, cnt[i]);
	}
	printf("%d\n", ans);
	return 0;
}