#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define sar(a,n) cout<<#a<<":";rep(kbrni,n)cout<<" "<<a[kbrni];cout<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define svecp(v) cout<<#v<<":";each(kbrni,v)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout<<" "<<kbrni;cout<<endl
#define smap(m) cout<<#m<<":";each(kbrni,m)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

const int MAX_N = 100005;

struct edge
{
    int u,v,cost,kind;
    bool operator< (const edge& another) const {
        return cost < another.cost;
    }
};

struct eda
{
    int to,cost,kind;
};

class UF {
private:
    int sz; vector<int> par,nrank;
public:
    UF(){}
    UF(int node_size){ sz = node_size; par.resize(sz),nrank.resize(sz,0); rep(i,sz) par[i] = i; }
    int find(int x){ if(par[x] == x){ return x; }else{ return par[x] = find(par[x]); } }
    void unite(int x,int y)
    { x = find(x),y = find(y); if(x == y) return;
    	if(nrank[x] < nrank[y]){ par[x] = y; }else{ par[y] = x; if(nrank[x] == nrank[y]) nrank[x]++; } }
    bool same(int x,int y){ return find(x) == find(y); }
};

void dfs(int u,int p,int flag,vector<edge>& vec,const set<int>* G,vector<int>& comp)
{
    comp[u] = flag;
    each(v,G[u]){
        if(v != p){
            dfs(v,u,flag,vec,G,comp);
        }
    }
}

bool trans(const int n,int ch,int& ans,vector<edge>& vec,set<int>* G,set<int>* use,set<P>* unuse)
{
    int diff = INF;
    int in = -1,out = -1;
    each(it,use[ch]){
        vector<int> comp(n,-1);
        int cri = -vec[it].cost;
        int id = -1;
        dfs(vec[it].u,vec[it].v,0,vec,G,comp);
        dfs(vec[it].v,vec[it].u,1,vec,G,comp);
        each(it2,unuse[ch^1]){
            int a = vec[it2.se].u,b = vec[it2.se].v;
            if(comp[a] != comp[b]){
                cri += vec[it2.se].cost;
                id = it2.se;
                break;
            }
        }
        if(id >= 0 && diff > cri){
            diff = cri;
            in = id,out = it;
        }
    }
    G[vec[out].u].erase(vec[out].v),G[vec[out].v].erase(vec[out].u);
    G[vec[in].u].insert(vec[in].v),G[vec[in].v].insert(vec[in].u);
    use[ch].erase(out);
    unuse[ch^1].erase(P(vec[in].cost,in));
    if(diff == INF){
        return false;
    }else{
        ans += diff;
        return true;
    }
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    while(1){
        int n,m,k;
        cin >> n >> m >> k;
        if(n == 0){
            break;
        }
        vector<edge> vec(m);
        int ans = 0;
        set<int> G[201];
        set<int> use[2];
        set<P> unuse[2];
        rep(i,m){
            int a,b,c,d;
            string hoge;
            cin >> a >> b >> c >> hoge;
            if(hoge == "A"){
                d = 0;
            }else{
                d = 1;
            }
            --a,--b;
            vec[i] = (edge){a,b,c,d};
        }
        int num[2] = {};
        sort(all(vec));
        UF uf(n);
        rep(i,m){
            int a = vec[i].u,b = vec[i].v;
            if(!uf.same(a,b)){
                uf.unite(a,b);
                G[a].insert(b),G[b].insert(a);
                ans += vec[i].cost;
                num[vec[i].kind]++;
                use[vec[i].kind].insert(i);
            }else{
                unuse[vec[i].kind].insert(P(vec[i].cost,i));
            }
        }
        if(num[0] + num[1] < n-1){
            cout << "-1\n";
            continue;
        }
        bool flag = false;
        rep(i,abs(k-num[0])){
            if(!trans(n,(k > num[0]),ans,vec,G,use,unuse)){
                cout << "-1\n";
                flag = true;
                break;
            }
        }
        if(!flag){
            cout << ans << "\n";
        }
    }
    return 0;
}



Measured memory_bytes: 3236