using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m, k) = (c[0], c[1], c[2]);
        var map = NArr(m);
        var tree = new List<(int to, long z)>[n];
        for (var i = 0; i < tree.Length; ++i) tree[i] = new List<(int to, long z)>();
        var uf = new UnionFindTree(n);
        foreach (var edge in map)
        {
            uf.Unite(edge[0] - 1, edge[1] - 1);
            tree[edge[0] - 1].Add((edge[1] - 1, edge[2]));
            tree[edge[1] - 1].Add((edge[0] - 1, edge[2]));
        }
        var mod = 1_000_000_007;
        var ans1 = 1L;
        var ans2 = 1L;
        var visited1 = new bool[n];
        var visited2 = new bool[n];
        for (var i = 0; i < n; ++i) if (uf.GetRoot(i) == i)
        {
            var min = 1L;
            var max = (long)k;
            DFS(i, k, 0, true, tree, visited1, ref min, ref max);
            ans1 = ans1 * (Math.Max(0, max - min + 1) % mod) % mod;
            min = 1L;
            max = k - 1;
            DFS(i, k - 1, 0, true, tree, visited2, ref min, ref max);
            ans2 = ans2 * (Math.Max(0, max - min + 1) % mod) % mod;
        }
        WriteLine((ans1 - ans2 + mod) % mod);
    }
    static void DFS(int cur, int k, long sum, bool minus, List<(int to, long z)>[] tree, bool[] visited, ref long min, ref long max)
    {
        visited[cur] = true;
        foreach (var next in tree[cur])
        {
            if (visited[next.to]) continue;
            if (minus)
            {
                max = Math.Min(max, next.z - sum - 1);
                min = Math.Max(min, next.z - sum - k);
            }
            else
            {
                min = Math.Max(min, 1 - next.z + sum);
                max = Math.Min(max, k - next.z + sum);
            }
            DFS(next.to, k, next.z - sum, !minus, tree, visited, ref min, ref max);
        }
    }
    class UnionFindTree
    {
        int[] roots;
        public UnionFindTree(int size)
        {
            roots = new int[size];
            for (var i = 0; i < size; ++i) roots[i] = -1;
        }
        public int GetRoot(int a)
        {
            if (roots[a] < 0) return a;
            return roots[a] = GetRoot(roots[a]);
        }
        public bool IsSameTree(int a, int b)
        {
            return GetRoot(a) == GetRoot(b);
        }
        public bool Unite(int a, int b)
        {
            var x = GetRoot(a);
            var y = GetRoot(b);
            if (x == y) return false;
            if (-roots[x] < -roots[y]) { var tmp = x; x = y; y = tmp; }
            roots[x] += roots[y];
            roots[y] = x;
            return true;
        }
        public int GetSize(int a)
        {
            return -roots[GetRoot(a)];
        }
    }
}