#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

#include<queue>

using namespace std;

#define maxn 21000

int nn,n;

int e[maxn],v[maxn],ne[maxn],w[maxn],fa[maxn];

void add(int x,int y,int z){

ne[++nn]=e[x],e[x]=nn,v[nn]=y,w[nn]=z;

}

struct node{

node *ch[2],*pre;

int maxx,val,rt;

}tree[maxn];

node *null;

void init(){

memset(e,0,sizeof(e));

nn=0;

null=&tree[0];

null->maxx=-0x3fffffff;

null->val=-0x3fffffff;

for(int i=1;i<=n;i++){

tree[i].pre=tree[i].ch[0]=tree[i].ch[1]=null;

tree[i].rt=1;

tree[i].maxx=0;

}

}

void up(node *x){

x->maxx=max(x->ch[0]->maxx,max(x->ch[1]->maxx,x->val));

}

void dfs(int x,int fa,int ww){

tree[x].pre=(&tree[fa]);

tree[x].val=tree[x].maxx=ww;

for(int i=e[x];i;i=ne[i])if(v[i]!=fa)dfs(v[i],x,w[i]);

}

void rotate(node *x){

node *y=x->pre,*z=y->pre;

int k=x==y->ch[0];

y->ch[!k]=x->ch[k];

x->ch[k]->pre=y;

x->ch[k]=y;

y->pre=x;

x->pre=z;

if(!y->rt)z->ch[z->ch[1]==y]=x;

else{

y->rt=0;

x->rt=1;

}

up(y);

}

void splay(node *x){

for(up(x);!x->rt;){

node *y=x->pre,*z=y->pre;

if(y->rt)rotate(x);

else if((z->ch[1]==y)==(y->ch[1]==x))rotate(y),rotate(x);

else rotate(x),rotate(x);

}

up(x);

}

node* acess(node *x){

node *y=null;

for(;x!=null;y=x,x=x->pre){

splay(x);

x->ch[1]->rt=1;

x->ch[1]=y;

y->rt=0;

up(x);

}

return y;

}

int ask(int a,int b){

acess(&tree[a]);

node *y=acess(&tree[b]);

splay(y);

if(y==(&tree[a]))return y->ch[1]->maxx;

int ma=y->ch[1]->maxx;

splay(&tree[a]);

return max(ma,tree[a].maxx);

}

void change(int a,int b){

splay(&tree[a]);

tree[a].val=b;

up(&tree[a]);

}

int cas;

char aa[10];

int main(){

cin>>cas;

while(cas--){

memset(fa,-1,sizeof(fa));

scanf("%d",&n);

init();

for(int i=1;i<n;i++){

int a,b,c;

scanf("%d%d%d",&a,&b,&c);

add(a,b,c);

add(b,a,c);

}

queue<int> jj;

jj.push(1);

tree[1].val=0;

tree[1].pre=null;

while(!jj.empty()){

int x=jj.front();

jj.pop();

for(int i=e[x];i;i=ne[i]){

if(&tree[v[i]]==tree[x].pre)continue;

tree[v[i]].pre=&tree[x];

tree[v[i]].val=tree[v[i]].maxx=w[i];

fa[v[i]]=x;

jj.push(v[i]);

}

}

while(1){

scanf("%s",aa);

if(aa[1]=='O')break;

if(aa[1]=='U'){

int a,b;

scanf("%d%d",&a,&b);

if(a==b){

printf("0\n");continue;}

printf("%d\n",ask(a,b));

}else{

int a,b;

scanf("%d%d",&a,&b);

if(fa[v[a<<1]]==v[(a<<1)-1]){

change(v[a<<1],b);

}else{

change(v[(a<<1)-1],b);

}

}

}

}

}