#include <iostream>
#include <vector>
#include <map>

using namespace std;

int main()
{
   int n,x,y,p,po;
   map<int,map<int,int> > graph;
   map<int,int> ch;
   vector<char> car;
   char ca,ti;
   while(cin>>n&&n!=0)
   {
       graph.clear();
       ch.clear();
       car.clear();
       po=0;
       for(int i=0;i<n;i++)
       {
           cin>>ca>>ti>>x>>y>>p;
           if(ch[x]==0)
           {
               ch[x]=po;
               po++;
               car.push_back(x);
           }
           if(ch[y]==0)
           {
               ch[y]=po;
               po++;
               car.push_back(x);
           }
           graph[ch[x]][ch[y]]=p;
           if(ca=='B')
            graph[ch[y]][ch[x]]=p;
       }
       for(int k=0;k<po;k++)
       {
           for(int i=0;i<po;i++)
           {
               for(int j=0;j<po;j++)
               {
                   if(graph[i].find(k)!=graph[i].end()&&graph[k].find(j)!=graph[k].end())
                   {
                       if(graph[i].find(j)!=graph[i].end())
                       {
                           graph[i][j]=min(graph[i][j],graph[i][k]+graph[k][j]);
                       }
                       else
                        graph[i][j]=graph[i][k]+graph[k][j];
                   }
               }
           }
       }

   }
    return 0;
}