#include <algorithm>
    #include <iostream>
    #include <sstream>
    #include <string>
    #include <vector>
    #include <queue>
    #include <set>
    #include <map>
    #include <cstdio>
    #include <cstdlib>
    #include <cctype>
    #include <cmath>

    using namespace std;

    int size[100000];
    int parent [100000];
    bool cafe[100000];
    long long ans;
    pair<pair<int, int>, int> arr[400000];
    int n, m, t, a, b, c, p;
    string str;



    bool cmp(const pair<pair<int, int>, int> &a, const pair<pair<int, int>, int> &b){
         if (a.second < b.second)
             return true;
         if (a.second > b.second)
             return false;
         return a.first < b.first;
    }

    int find_set(int v) {
                    if (v == parent[v])
                            return v;
                    return parent[v] = find_set(parent[v]);
    }

    bool union_sets(int a, int b) {
                    a = find_set(a);
                    b = find_set(b);
                    if (a == b)
                            return false;
                    if (size[a] < size[b]) {
                            int temp = a;
                            a = b;
                            b = temp;
                    }
                    parent[b] = a;
                    size[a] += size[b];
                    return true;
    }

    void MST() {
                    for (int i = 0; i < n; i++) {
                            if (cafe[i]) {
                                    parent[i] = p;
                                    size[p]++;
                            }
                            else {
                            parent[i] = i;
                                size[i] = 1;
                  }
                    }

                    for (int i = 0; i < m; i++) {
                            if (union_sets(arr[i].first.first, arr[i].first.second)) {
                                    ans += arr[i].second;
                    if (size[arr[i].first.first] == n || size[arr[i].first.second] == n)
                                    return;
                            }

                    }
    }

    int main()
    {
        //freopen("input.txt","r",stdin);
                    cin >> t;
                    while(t--) {
                       ans = 0;
                            scanf("%d%d",&n,&m);

            getline(cin, str);
            getline(cin, str);
           for (int j = 0; j < n; j++)
           {
                 cafe[j] = (str[j] == 'R');
                 if(cafe[j]) p = j;
                 size[j] = 0;
                }

                            for (int j = 0; j < m; j++)
                            {
                                scanf ("%d%d%d", &a, &b, &c);
                                a--;
                                b--;
                                if (c < 0) {
                                       ans += c;
                                       c = 0;
                                    }
                              arr[j] = make_pair(make_pair(a, b), c);
                            }

                            sort(arr, arr + m, cmp);
                            MST();
                            cout << ans << endl;
            }
            //      system("pause");

          return 0;
    }