#include <bits/stdc++.h>
using namespace std;
const int inf = (int)1e5 + 5;
const int green = 0, red = 1, white = 2;
class Tree {
public:
int n;
vector<vector<int>> adj, dp;
string str;
// dp[i][d] is the answer when the highest node is i and it has
// color d.
Tree(int n) {
this->n = n;
adj.resize(n);
dp.resize(n, vector<int>(3, inf));
}
void dfs(int src, int par) {
// Start with no children.
if (str[src] == 'P') {
dp[src][green] = 0;
}
if (str[src] == 'S') {
dp[src][red] = 0;
}
if (str[src] == 'C') {
dp[src][white] = 0;
}
for (auto child : adj[src]) {
if (child == par) {
continue;
}
dfs(child, src);
vector<int> ndp(3, inf);
for (int d : {green, red, white}) {
for (int now : {green, red, white}) {
// Delete the edge between them.
ndp[d] = min(ndp[d], 1 + dp[src][d] + dp[child][now]);
// Keep the edge between them.
int nxt = -1;
if (d == white) {
nxt = now;
} else if (now == white) {
nxt = d;
} else {
if (d == now) {
nxt = d;
}
}
if (nxt == -1) {
continue;
}
ndp[nxt] = min(ndp[nxt], dp[src][d] + dp[child][now]);
}
}
swap(dp[src], ndp);
}
}
};
void solve() {
int n;
cin >> n;
Tree t(n);
for (int i = 1; i < n; i++) {
int p;
cin >> p;
p--;
t.adj[i].push_back(p);
t.adj[p].push_back(i);
}
cin >> t.str;
t.dfs(0, -1);
auto &dp = t.dp;
cout << min({dp[0][green], dp[0][red], dp[0][white]}) << "\n";
}
int main() {
int t;
cin >> t;
for (int i = 0; i < t; i++) {
solve();
}
return 0;
}
