#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(ll (i) = (0);(i) < (n);++i)
#define PB push_back
#define MP make_pair
#define FI first
#define SE second
#define SHOW1d(v,n) {REP(WW,n)cerr << v[WW] << ' ';cerr << endl << endl;}
#define SHOW2d(v,WW,HH) {REP(W_,WW){REP(H_,HH)cerr << v[W_][H_] << ' ';cerr << endl;}cerr << endl;}
#define ALL(v) v.begin(),v.end()
#define Decimal fixed<<setprecision(20)
#define INF 1000000000
#define LLINF 1000000000000000000LL
#define MOD 1000000007

typedef long long ll;
typedef pair<ll,ll> P;

struct UF{
	vector<int> par;
	vector<int> sz;
	UF(int n):par(n),sz(n) {
		for(int i = 0; i < n; i++){
			par[i] = i;sz[i] = 1;
		}
	}
	int find(int x) {
		if (par[x] == x) return x;
		else return par[x] = find(par[x]);
	}
	void unite(int x, int y) {
		x = find(x); y = find(y);
		if (x == y) return;
		par[x] = y;
		sz[x] += sz[y];
	}
	bool same(int x, int y) { return find(x) == find(y); }
	int size(int n){return sz[find(n)];}
};

struct LCA{
	vector<vector<pair<int,int> > > g;
	vector<vector<int> > parent;
	vector<int> depth;
	UF uf;
	int sz;
	vector<bool> inited;
		
	LCA(int n):g(n),parent(20,vector<int>(n)),
	inited(n,false),depth(n),uf(n){sz = n;}
	
	void add_edge(int u,int v,int w = 1){
		if(uf.same(u,v))return;
		g[v].PB(MP(u,w));
		g[u].PB(MP(v,w));
		uf.unite(v,u);
	}
		
	void dfs(int v,int p,int d){
		inited[v] = true;
		parent[0][v] = p;
		depth[v] = d;
		REP(i,g[v].size()){
			if(g[v][i].FI != p)dfs(g[v][i].FI,v,d+1);
		}
	}
	
	void init(){
		REP(i,sz)if(!inited[i])dfs(uf.find(i),-1,0);
		REP(k,19){
			REP(i,sz){
				if(parent[k][i] < 0)parent[k+1][i] = -1;
				else parent[k+1][i] = parent[k][parent[k][i]];
			}
		}
	}
	
	int ret_lca(int a,int b){
		
		if(!uf.same(a,b))return -1;
		
		if(depth[a] > depth[b])swap(a,b);
		REP(k,20){
			if((depth[b] - depth[a])>>k&1)b = parent[k][b];
		}
		if(a == b)return a;
		
		for(int k = 19;k >= 0;k--){
			if(parent[k][a] != parent[k][b])
			{
				a = parent[k][a];
				b = parent[k][b];
			}
		}
		return parent[0][a];
	}
	
};

vector<vector<int>> v(111111);
int mp[111111];
int color[111111];
LCA lca(111111);

struct seica {
	set<pair<int,int>> s;
	int ans = 0;
	int top = 0;
	void add(int a){
		if(s.size() != 0){
			int ret = INF; 
			auto now = s.lower_bound(MP(a, lca.depth[a]));
			if(now != s.end()){
				int tmp = lca.ret_lca(a, now->FI);
				ret = min(ret, abs(lca.depth[a] - lca.depth[tmp]));
				tmp = lca.ret_lca(top, tmp);
				ans += abs(lca.depth[top] - lca.depth[tmp]);
				top = tmp;
			}
			if(now != s.begin()){
				now--;
				int tmp = lca.ret_lca(a, now->FI);
				ret = min(ret, abs(lca.depth[a] - lca.depth[tmp]));
				tmp = lca.ret_lca(top, tmp);
				ans += abs(lca.depth[top] - lca.depth[tmp]);
				top = tmp;
			}
			if(ret == INF)ret = 0;
			ans += ret;
		}
		else{
			top = a;
		}
		s.insert(MP(a, lca.depth[a]));
	}
	
	void remove(int a) {
		auto now = s.lower_bound(MP(a, lca.depth[a]));
		int ret = INF;
		now++;
		if(now != s.end()){
			int tmp = lca.ret_lca(a, now->FI);
			ret = min(ret, abs(lca.depth[a] - lca.depth[tmp]));
		}
		now--;
		if(now != s.begin()){
			now--;
			int tmp = lca.ret_lca(a, now->FI);
			ret = min(ret, abs(lca.depth[a] - lca.depth[tmp]));
			now++;
		}
		if(ret == INF)ret = 0;
		ans -= ret;
		s.erase(now);
		if(s.size() > 0){
			int a = s.begin() -> FI;
			auto hoge = s.end();hoge--;
			int b = hoge -> FI;
			int tmp = lca.ret_lca(a, b);
			ans -= abs(lca.depth[tmp] - lca.depth[top]);
			top = tmp;
		}
	}
};

seica ixmel[111111];
int sum;
void dfs(int a,int pre){
	REP(i,v[a].size()){
		if(v[a][i] == pre)continue;
		mp[v[a][i]] = sum;sum++;
		lca.add_edge(mp[a], mp[v[a][i]]);
		dfs(v[a][i], a);
	}
}

int main(){
	
	int n;cin >> n;
	REP(i,n-1){
		int a, b;cin >> a >> b;
		a--;b--;
		v[a].PB(b);
		v[b].PB(a);

	}
	
	REP(i,n)cin >> color[i];
	mp[0] = sum;sum++;
	dfs(0, -1);
	lca.init();
	REP(i,n)ixmel[color[i]].add(mp[i]);
	
	int q;cin >> q;
	REP(i,q){
		char c;cin >> c;
		if(c == 'U'){
			int a, b;cin >> a >> b;a--;
			ixmel[color[a]].remove(mp[a]);
			ixmel[b].add(mp[a]);
			color[a] = b;
		}
		else{
			int a;cin >> a;
			if(ixmel[a].s.size())cout << ixmel[a].ans << endl;
			else cout << -1 << endl;
		}
	}
	
	return 0;
}



Measured memory_bytes: 54224