using System;
using System.Linq;
using System.Collections.Generic;
//using System.Numerics;
using Debug = System.Diagnostics.Debug;
using SB = System.Text.StringBuilder;
using Number = System.Int64;
using KV = System.Collections.Generic.KeyValuePair<int, long>;
namespace Program {
    public class Solver {
        public void Solve() {
            for (; ; ) {
                var n = ri;
                var m = ri;
                var k = ri;
                if (n == 0) return;
                var f = new int[m];
                var t = new int[m];
                var w = new int[m];
                var c = new int[m];
                for (int i = 0; i < m; i++) {
                    f[i] = ri - 1;
                    t[i] = ri - 1;
                    w[i] = ri;
                    c[i] = sc.Char() - 'A';
                }
                Func<int, int[]> func = v => {
                    var cnt = 0;
                    var sum = 0;
                    var s = new DisjointSet(n);
                    foreach (var id in Enumerate(m, x => x).OrderBy(x => c[x] == 0 ? w[x] + v : w[x]).ThenBy(x => c[x])) {
                        if (s.Unite(f[id], t[id])) {
                            sum += c[id] == 0 ? w[id] + v : w[id];
                            cnt += c[id] ^ 1;
                        }
                    }
                    return new int[] { sum, cnt, s.Size(0) };
                };
                var l = -300; var r = 300;
                var ok = true;
                ok &= func(l)[2] == n;
                ok &= func(l)[1] >= k;
                ok &= func(r)[1] <= k;
                if (!ok) {
                    Console.WriteLine(-1);
                    continue;
                }
                while (r - l > 1) {
                    var x = (l + r) / 2;
                    if (func(x)[1] >= k) l = x;
                    else r = x;
                }
                var ans = func(l)[0] - l * k;
                Debug.WriteLine(func(l).AsJoinedString());
                Console.WriteLine(ans);

            }
        }
        const long INF = 1L << 60;

        //int[] dx = { -1, 0, 1, 0 };
        //int[] dy = { 0, 1, 0, -1 };
        int ri { get { return sc.Integer(); } }
        long rl { get { return sc.Long(); } }
        double rd { get { return sc.Double(); } }
        string rs { get { return sc.Scan(); } }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());

        static T[] Enumerate<T>(int n, Func<int, T> f) {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f(i);
            return a;
        }

        static public void Swap<T>(ref T a, ref T b) {
            var tmp = a;
            a = b;
            b = tmp;
        }
    }
}

#region main

static class Ex {
    static public string AsString(this IEnumerable<char> ie) {
        return new string(ie.ToArray());
    }

    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") {
        return string.Join(st, ie.Select(x => x.ToString()).ToArray());
        //return string.Join(st, ie);
    }

    static public void Main() {
        Console.SetOut(new System.IO.StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        var solver = new Program.Solver();
        solver.Solve();
        Console.Out.Flush();
    }
}

#endregion
#region Ex

namespace Program.IO {
    using System.IO;
    using System.Text;
    using System.Globalization;

    public class Printer: StreamWriter {
        public override IFormatProvider FormatProvider {
            get { return CultureInfo.InvariantCulture; }
        }
        public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
    }

    public class StreamScanner {
        public StreamScanner(Stream stream) {
            str = stream;
        }

        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream {
            get { return isEof; }
        }

        private byte read() {
            if (isEof) return 0;
            if (ptr >= len) {
                ptr = 0;
                if ((len = str.Read(buf, 0, 1024)) <= 0) {
                    isEof = true;
                    return 0;
                }
            }
            return buf[ptr++];
        }

        public char Char() {
            byte b = 0;
            do b = read(); while ((b < 33 || 126 < b) && !isEof);
            return (char)b;
        }

        public string Scan() {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b);
            return sb.ToString();
        }

        public string ScanLine() {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n' && b != 0; b = (char)read()) if (b != '\r') sb.Append(b);
            return sb.ToString();
        }

        public long Long() {
            return isEof ? long.MinValue : long.Parse(Scan());
        }

        public int Integer() {
            return isEof ? int.MinValue : int.Parse(Scan());
        }

        public double Double() {
            return isEof ? double.NaN : double.Parse(Scan(), CultureInfo.InvariantCulture);
        }
    }
}

#endregion
#region DisjointSet
public class DisjointSet {
    int[] par;
    byte[] rank;
    public DisjointSet(int n) {
        par = new int[n];
        for (int i = 0; i < n; i++)
            par[i] = -1;
        rank = new byte[n];
    }
    public int this[int id] {
        get {
            if ((par[id] < 0)) return id;
            return par[id] = this[par[id]];
        }
    }
    public bool Unite(int x, int y) {
        x = this[x]; y = this[y];
        if (x == y) return false;
        if (rank[x] < rank[y]) { var z = x; x = y; y = z; }
        par[x] += par[y];
        par[y] = x;
        if (rank[x] == rank[y])
            rank[x]++;
        return true;
    }
    public int Size(int x) { return -par[this[x]]; }
    public bool IsUnited(int x, int y) { return this[x] == this[y]; }

}
#endregion


Measured memory_bytes: 10448