#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10;

int n , m;
int h[N] , tot;
struct node{
	int to , nxt , dis;	
} e[N];

inline void add(int u , int v , int w){
	e[++tot].to = v;
	e[tot].dis = w;
	e[tot].nxt = h[u];
	h[u] = tot;
}

int dep[N] , sze[N] , fa[N] , hson[N] , dfn[N] , iddfn[N] , cnt , A[N] , top[N];
inline void dfs(int x , int f){
	dep[x] = dep[f] + 1 , sze[x] = 1 , fa[x] = f , hson[x] = 0;
	for (int i = h[x] ; i ; i = e[i].nxt){
		int y = e[i].to , w = e[i].dis;
		if(y == f) continue;
		dfs(y , x);
		sze[x] += sze[y];
		if(sze[y] > sze[hson[x]]) hson[x] = y;
 	}
}

inline void hld(int x , int topf){
	dfn[x] = ++cnt , iddfn[dfn[x]] = x ; top[x] = topf; 
	if(hson[x]) hld(hson[x] , topf);
	else return;
	for (int i = h[x] ; i ; i = e[i].nxt){
		int y = e[i].to , w = e[i].dis;
		if(y == fa[x] || y == hson[x]) continue;	
		hld(y , y);
		A[dfn[y]] = w;
	} 
}

namespace SegmentTree{
#define lc (u << 1)
#define rc (u << 1 | 1)
#define mid ((l + r) >> 1)
	int T[N << 2];
	
	inline void maintain(int u){
		T[u] = max(T[lc] , T[rc]);	
	}
	
	inline void Build(int u , int l ,int r){
		if(l == r){
			T[u] = A[l];
			return;
		}
		Build(lc , l , mid) , Build(rc , mid + 1 , r);
		maintain(u);
	}
	
	inline void Modify(int u , int l , int r , int p , int x){
		if(l == r){
			T[u] = x;
			return;
		}
		if(p <= mid) Modify(lc , l , mid , p , x);
		else Modify(rc , mid + 1 , r , p , x);
		maintain(u);
	}
	
	inline int Ask(int u , int l , int r , int L , int R){
		if(l >= L && r <= R){
			return T[u];
		}
		if(R <= mid) return (lc , l , mid , L , R);
		if(L > mid) return (rc , mid + 1 , r , L , R);
		return max(Ask(lc , l , mid , L , R) , Ask(rc , mid + 1 , r , L , R));
	}
#undef lc
#undef rc
#undef mid
}

inline int QMax(int u ,int v){
	int res = -0x3f3f3f3f;
	while(top[u] != top[v]){
		if(dep[top[u]] < dep[top[v]]) swap(u , v);
		res = max(res , SegmentTree::Ask(1 , 1 , n , dfn[top[u]] , dfn[u]));
		u = fa[top[u]];
	}
	if(dep[u] > dep[v]) swap(u , v);
	res = max(res , SegmentTree::Ask(1 , 1 , n , dfn[u] + 1 , dfn[v]));
	return res;
}

signed main(){
	ios::sync_with_stdio(false) , cin.tie(0);
	cin >> n;
	for (int i = 1 ; i < n ; i++){
		int u , v , w;
		cin >> u >> v >> w;
		add(u , v , w);
		add(v , u , w);
	}	
	
	dfs(1 , 0) , hld(1 , 1) , SegmentTree::Build(1 , 1 , n);
	
	string s;
	while(1){
		cin >> s;
		int x , y;
		if(s[0] == 'D') break;
		cin >> x >> y;	
		if(s[0] == 'Q'){
			if(x == y) cout << "0\n";
			else cout << QMax(x , y) << "\n";
		}
		if(s[0] == 'C'){
			x = x * 2 - 1;
			int a = e[x].to , b = e[x + 1].to;
			if(fa[a] == b) x = a;
			else x = b;
			SegmentTree::Modify(1 , 1 , n , dfn[x] , y);
		}
	}
	
	return 0;
}