#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 0x3f3f3f3f3f3f3f3f;
typedef multiset<ll>::iterator itt;
const int N = 5e5+11, P = 998244353;

int n;
char c[N];
ll f[N], ans, cnt[N];
int tot, head[N], ver[N], nex[N];

void add(int x, int y){
	nex[++tot] = head[x];
	head[x] = tot;
	ver[tot] = y;
}

void dfs(int x, int fa){
//	cnt[x] += (c[x] == 'B' ? 1 : c[x] == 'W' ? -1 : 0);
	for(int i=head[x]; i; i=nex[i]) if(ver[i] != fa){
		int y = ver[i];
		dfs(y, x);
		cnt[x] += cnt[y];
	} // if(cnt[x] == 0) printf("x=%d\n",x), ans ++;
	ans += (!cnt[x]);
}

void work(){
	scanf("%d",&n); ans = tot = 0;
	for(int i=0;i<=n;i++) cnt[i] = c[i] = head[i] = 0;
	for(int x,i=2;i<=n;i++) scanf("%d",&x), add(x, i), add(i, x);
	
	scanf("%s",c + 1); 
	for(int i=1;i<=n;i++) cnt[i] = (c[i] == 'B' ? 1 : -1);
	dfs(1, 0); printf("%lld\n",ans);
}

int main(){
	int t = 1; scanf("%d",&t);
	while(t--) work(); return 0;
}