#include<iostream>

 #include<cstdio>

 #include<cstring>

 #define maxn 100009

 using namespace std;

 int head[maxn],next[maxn*],point[maxn],son[maxn],size_k[maxn],id[maxn],value[maxn],now=,father[maxn],top[maxn];

 int x[maxn],y[maxn],v[maxn],tree[maxn*],pos=,deep[maxn],n;

 int read()

 {

     int x=,f=;char ch=getchar();

     while(ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}

     while(ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}

     return x*f;

 }

 void add(int x,int y,int v)

 {

     next[++now]=head[x];head[x]=now;

     point[now]=y;value[now]=v;

 }

 int dfs(int k,int fa)

 {

     deep[k]=deep[fa]+;

     father[k]=fa;

     size_k[k]=;

     int max_x=-;

     son[k]=-;

     for(int i=head[k];i;i=next[i])

     {

         if(point[i]==fa)continue;

         dfs(point[i],k);

         size_k[k]+=size_k[point[i]];

         if(size_k[point[i]]>max_x)

         {

                         max_x=size_k[point[i]];

             son[k]=point[i];

         }

     }

 }

 void dfs2(int k,int fa,int pa)

 {

     id[k]=++pos;

     top[k]=pa;

     if(son[k]!=-)dfs2(son[k],k,pa);

     for(int i=head[k];i;i=next[i])

     {

         if(point[i]!=fa && point[i]!=son[k])dfs2(point[i],k,point[i]);

     }

 }

 void update(int node,int l,int r,int pos,int x)

 {

     if(l+==r){tree[node]=x;return;}

     int mid=(l+r)>>;

     if(pos<mid)update(node*,l,mid,pos,x);

     else update(node*+,mid,r,pos,x);

     tree[node]=max(tree[node*],tree[node*+]);

 }

 int query(int node,int l,int r,int ql,int qr)

 {

     if(ql<=l && r<=qr)return tree[node];

     int mid=(l+r)>>;

     int ans=-0x3f3f3f3f;

     if(ql<mid)ans=max(query(node<<,l,mid,ql,qr),ans);

     if(mid<qr)ans=max(query(node<<|,mid,r,ql,qr),ans);

     return ans;

 }

 int find(int x,int y)

 {

     int fa=top[x],fb=top[y],temp=;

     while(fa!=fb)

     {

         if(deep[fa]<deep[fb])

         {

             swap(fa,fb);

             swap(x,y);

         }

         if(id[fa]>id[x]+)return -;

         temp=max(temp,query(,,pos+,id[fa],id[x]+));

         x=father[fa];fa=top[x];

     }

     if(x==y)return temp;

     if(deep[x]<deep[y])swap(x,y);

     if(id[y]+>id[x]+)return -;

     return max(temp,query(,,pos+,id[son[y]],id[x]+));

 }

 int main()

 {

     int t;

     t=read();

     while(t--)

     {

         now=;

         memset(head,,sizeof(head));

         memset(tree,,sizeof(tree));

         n=read();

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

         {

             x[i]=read();y[i]=read();v[i]=read();

             add(x[i],y[i],v[i]);

             add(y[i],x[i],v[i]);

         }

         deep[]=;

         dfs(,);

         dfs2(,,);

         for(int i=;i<=n-;i++)

         {

             int u=deep[x[i]]>deep[y[i]]?x[i]:y[i];

             update(,,pos+,id[u],v[i]);

         }

                 int xx,yy;

         char ch[];

         while(true)

         {

             scanf("%s",ch);

             if(ch[]=='D')break;

             xx=read();yy=read();

             if(ch[]=='Q')

             {

                 printf("%d\n",find(xx,yy));

             }

             else if(ch[]=='C')

             {

                 int u=deep[x[xx]]>deep[y[xx]]?x[xx]:y[xx];

                 update(,,pos+,id[u],yy);

             }

             else if(ch[]=='D')

             {

                                 break;

             }

         }

     }

     return ;

 }