#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
int main(){
  int N, M, K;
  cin >> N >> M >> K;
  vector<vector<pair<int, int>>> E(N);
  for (int i = 0; i < M; i++){
    int X, Y, Z;
    cin >> X >> Y >> Z;
    X--;
    Y--;
    E[X].push_back(make_pair(Z, Y));
    E[Y].push_back(make_pair(Z, X));
  }
  vector<long long> ans(2, 1);
  for (int i = 0; i < 2; i++){
    if (i == 1){
      K--;
    }
    vector<bool> used(N, false);
    vector<long long> a(N), b(N);
    for (int j = 0; j < N; j++){
      if (!used[j]){
        used[j] = true;
        a[j] = 1;
        b[j] = 0;
        long long mn = 1, mx = K;
        vector<long long> s;
        bool ok = true;
        queue<int> Q;
        Q.push(j);
        while (!Q.empty()){
          int v = Q.front();
          Q.pop();
          if (a[v] == 1){
            mn = max(mn, 1 - b[v]);
            mx = min(mx, K - b[v]);
          }
          if (a[v] == -1){
            mn = max(mn, b[v] - K);
            mx = min(mx, b[v] - 1);
          }
          for (auto P : E[v]){
            int w = P.second;
            if (!used[w]){
              used[w] = true;
              a[w] = -a[v];
              b[w] = P.first - b[v];
              Q.push(w);
            } else if (a[v] != a[w]){
              if (b[v] + b[w] != P.first){
                ok = false;
              }
            } else {
              if (a[v] == 1 && a[w] == 1){
                s.push_back(P.first - b[v] - b[w]);
              }
              if (a[v] == -1 && a[w] == -1){
                s.push_back(b[v] + b[w] - P.first);
              }
            }
          }
        }
        if (!ok){
          ans[i] = 0;
        } else {
          sort(s.begin(), s.end());
          s.erase(unique(s.begin(), s.end()), s.end());
          if (s.size() >= 2){
            ans[i] = 0;
          } else if (s.size() == 1){
            if (s[0] % 2 == 1){
              ans[i] = 0;
            } else {
              if (s[0] / 2 < mn || s[0] / 2 > mx){
                ans[i] = 0;
              }
            }
          } else {
            long long tmp = max(mx - mn + 1, (long long) 0);
            ans[i] *= tmp;
            ans[i] %= MOD;
          }
        }
      }
    }
  }
  cout << (ans[0] - ans[1] + MOD) % MOD << endl;
}