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

const int N = 1e5 + 10;
int n, a[N];
int fa[N], dep[N], sz[N], son[N];
int clk, top[N], dfn[N];
int id, head[N << 1], to[N << 1], nxt[N << 1];
ll w[N << 1], val[N << 2];
struct edge{
	int u, v;
	ll w;
} e[N];

void add(int u, int v, ll ww){
	to[++id] = v, w[id] = ww;
	nxt[id] = head[u], head[u] = id;
}

void dfs(int u, int father){
	sz[u] = 1;
	for(int i=head[u];i;i=nxt[i]){
		int v = to[i];
		if(v == father)
			continue;
		dep[v] = dep[u] + 1, fa[v] = u;
		a[v] = e[i].w;
		dfs(v, u);
		sz[u] += sz[v];
		if(!son[u] || sz[v] > sz[son[u]])
			son[u] = v;
	}
}

void build(int u, int t){
	dfn[u] = ++clk;
	top[u] = t;
	if(son[u])
		build(son[u], t);
	for(int i=head[u];i;i=nxt[i]){
		int v = to[i];
		if(v == fa[u])
			continue;
		if(v != son[u])
			build(v, v);
	}
}

#define ls(o) (o << 1)
#define rs(o) (o << 1 | 1)

void update(int o, int l, int r, int p, ll x){
	if(l == r){
		val[o] = x;
		return ;
	}
	int mid = (l + r) >> 1;
	if(p <= mid)
		update(ls(o), l, mid, p, x);
	else
		update(rs(o), mid + 1, r, p, x);
	val[o] = max(val[ls(o)], val[rs(o)]);
}

ll query(int o, int l, int r, int s, int t){
	if(l >= s && r <= t)
		return val[o];
	int mid = (l + r) >> 1;
	ll res = -1e18;
	if(s <= mid)
		res = max(res, query(ls(o), l, mid, s, t));
	if(t > mid)
		res = max(res, query(rs(o), mid + 1, r, s, t));
	return res;
}

ll query_ans(int u, int v){
	if(u == v)
		return 0;
	ll res = -1e18;
	while(top[u] != top[v]){
		if(dep[top[u]] < dep[top[v]])
			swap(u, v);
		res = max(res, query(1, 1, n, dfn[top[u]], dfn[u]));
		u = fa[top[u]];
	}
	if(dep[u] > dep[v])
		swap(u, v);
	res = max(res, query(1, 1, n, dfn[u] + 1, dfn[v]));//注意维护的是边权 
	return res;
}

int main(){
	scanf("%d", &n);
	for(int i=1,u,v;i<n;i++){
		ll ww;
		scanf("%d%d%lld", &u, &v, &ww);
		add(u, v, ww), add(v, u, ww);
		e[i] = (edge){u, v, ww};
	}
	dfs(1, 0);
	build(1, 1);
	for(int u=1;u<=n;u++)
		update(1, 1, n, dfn[u], a[u]);
	char op[20];
	while(~scanf("%s", op)){
		int a, b;
		ll ww;
		if(op[0] == 'D')
			break;
		if(op[0] == 'C'){
			scanf("%d%lld", &a, &ww);
			if(dep[e[a].u] > dep[e[a].v])
				b = e[a].u;
            else
				b = e[a].v;
            update(1, 1, n, dfn[b], ww);
		}
		else{
			scanf("%d%d", &a, &b);
			printf("%lld\n", query_ans(a, b));
		}
	}
	return 0;
}