#include <list>
#include<string.h>
using namespace std;
#include <queue>
  std::queue<int> q; 

# define maxedges 10009
# define maxnodes  10009
# define max 10009
class Graph

{
   private:
  

     struct ListNode

     {

      long long int name;
      long long int pos;
      long long int w;

        struct ListNode *next;      //This creates the same ListNode structure for the next and down pointers each one will have a name, a next, and a down.

        struct ListNode *down;

      };



       ListNode *head;

       ListNode *down_head;



    public:


      Graph() //Constructor

      {

         head = NULL;     //in-line initializations of head and down_head

         down_head = NULL;

      }



         void Build_Network(); //This function will prompt the user for all of the information, as well as perform the necessary linked list operations

         void Display();     
         void display2(long long,long long);     //This function will print out the linked list in a manner that is easily read.



};



#endif //Ends the definition of GRAPH_H



void Graph::Build_Network()

{

   ListNode *newNode;  //This is the new vertex

   ListNode *nodePtr;   //Traversing pointer

   ListNode *downPtr;  //Edge/Adjacent Vertex Traversing pointer


   long long int  num_Nodes,vertex;
   static long long int    i,j,position[100],color[maxnodes],d[maxnodes],count;

   long long int  V_Name[maxnodes],p[maxnodes],t; 
      long long int  E_Name[maxedges+maxedges],v1[maxedges],v2[maxedges];
      static long long  int  state[maxnodes],sum,v,a,b,top,big;
      char str[10];
      



   
       
       //cin>>t;
       scanf("%I64d" ,&t);
       printf("\n");
      while(t)
  //mainwhilet
  {
          
   
    //cin>>num_Nodes;
    scanf("%I64d" ,&num_Nodes);
    long long  int num_Edges;


            
            num_Edges=num_Nodes-1;


     for( i = 0; i<num_Nodes; i++)

    //ifor 
     {

         V_Name[i]=i+1;
         color[i+1]=0;
         d[i+1]=max;
         p[i+1]=0;
         
          
         
      
         
         newNode = new ListNode;

         newNode->name = V_Name[i];



         newNode->next = NULL;

         newNode->down = NULL;

// Building the Vertex List

         if(!head)

            head = newNode;

         else

         {

            nodePtr = head;

            while(nodePtr->next)

            nodePtr = nodePtr->next;

            nodePtr->next = newNode;

           }

}//endifor
           


        for( j=0; j<num_Edges; j++)

      //jfor   
      {
               
        
           
           cin>>v1[j]>>v2[j]>>E_Name[v1[j]+v2[j]+v1[j]*v2[j]];
          // scanf("%I64d %I64d %I64d" ,&v1[j],&v2[j],&E_Name[v1[j]+v2[j]+v1[j]*v2[j]]);
           
            

        
        
        ListNode *nodePtr;
        ListNode *downPtr;
            nodePtr = head;
           
            while(nodePtr)  //continue through all vertices

    {
          vertex=nodePtr->name;
         if(nodePtr->name==v1[j])
         break;
         else
      
          nodePtr=nodePtr->next;
          }
          

            ListNode *downNode;

            down_head =nodePtr->down;

            downNode = new ListNode;
           downNode->name=v2[j];
            downNode->w=E_Name[j];
            downNode->pos=j+1;
            
          
        

            downNode->down = NULL;

            if(!down_head)

            {

               nodePtr->down = downNode;

               down_head = downNode;

            }

            else

            {

               downPtr = down_head;


               while(downPtr->down)

                     downPtr = downPtr->down;


              downPtr->down = downNode;

            }
        
              
             
  nodePtr = head;
           
            while(nodePtr)  //continue through all vertices

    {
          vertex=nodePtr->name;
         if(nodePtr->name==v2[j])
         break;
          else
          nodePtr=nodePtr->next;
          }

            ListNode *downNode1;

            down_head =nodePtr->down;

            downNode1 = new ListNode;
            
            
          
          
            downNode1->name = v1[j];
            downNode1->w=E_Name[j];
            downNode1->pos=j+1;

            downNode1->down = NULL;



            if(!down_head)

            {

               nodePtr->down = downNode1;

               down_head = downNode1;

            }

            else

            {

               downPtr = down_head;


               while(downPtr->down)

                     downPtr = downPtr->down;


              downPtr->down = downNode1;

            }
         }

      
              
     while(1)
    {              
   //cin>>str;
   scanf("%s",&str);
  while(!q.empty())
  q.pop();
   if(strcmp(str,"DONE")==0)break;
   for(i=0;i<num_Nodes;i++)
   {
                           color[i+1]=0;
         d[i+1]=max;
         p[i+1]=0;
         }
   if(strcmp(str,"CHANGE")==0)
          {
                             // cin>>a>>b;
                             scanf("%I64d %I64d" ,&a,&b);
                             
                              E_Name[v1[a-1]+v2[a-1]+v1[a-1]*v2[a-1]]=b;
                             
          }
   
          if(strcmp(str,"QUERY")==0)
          {
               a=0,b=0;                    
             //cin>>a>>b;
              scanf("%I64d %I64d" ,&a,&b);
             nodePtr = head; 
             color[a]=11;
             d[a]=0;
             p[a]=0;
             q.push(a);
             while(!q.empty())
             {
                              top=q.front();
                            // cout<<"\n topt os "<<top<<"\n";
                              nodePtr=head;
                              while(nodePtr)
                              {
                                   if(nodePtr->name==top)
                                   break;
                                   else         
                                nodePtr=nodePtr->next;            
                              }
                           
                              downPtr=nodePtr->down;
                              while(downPtr)
                              {
                                           vertex= downPtr->name;
                                         //  cout<<"\n adjacent down--vertex"<<downPtr->name;
                                         //  cout<<"\n colrvertex"<<color[vertex];
                                          if(color[vertex]==0)
                                          {
                                          //    cout<<"\ncolr =0";
                                              color[vertex]=11;
                                              p[vertex]=top;
                                             // cout<<"\n d--top"<<d[top];
                                             //  cout<<"\n E--vertex"<<E_Name[vertex+top];
                                              d[vertex]=d[top]+E_Name[vertex+top+vertex*top];
                                              if(d[vertex]>big) big=d[vertex];
                                              q.push(vertex);
                                            
                                           }
                                            
                                            if(vertex==b) 
                                            goto s20;
                                            downPtr= downPtr->down;        
                              }
                              q.pop();
                              color[top]=2;
             }
                              
                              
             
             


                  
                        
                                     
                  

                                  
          
          
        s20:  
                         cout<<d[vertex]<<"\n";
          
          
          } //endif  
          
          }//big while                   
                   
               
t--;
}
}





int main()
{
  
    Graph s;
    s.Build_Network();
 
   
    return 0;
}

ListNode *newNode = NULL;  //This is the new vertex

   ListNode *nodePtr = NULL;   //Traversing pointer

   ListNode *downPtr = NULL;  //Edge/Adjacent Vertex Traversing pointer[/code]
and i also did downnode->next=NULL in 
[code]while(nodePtr)  //continue through all vertices

    {

         if(nodePtr->name==v1[j])
         break;
          else
          nodePtr=nodePtr->next;
          }

            ListNode *downNode1 = NULL;

            down_head =nodePtr->down;

            downNode1 = new ListNode;

            downNode1->name = v1[j];

            downNode1->down = NULL;
		downNode->next = NULL; //!!!!!!!!!