#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#include <list>
#include <atcoder/all>
#define popcount __builtin_popcount
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<int, int> P;
int n, m;
ll k;
ll v[100010];
int p[100010];
using mint=modint1000000007;
vector<P> g[100010];
int main()
{
	cin>>n>>m>>k;
	for(int i=0; i<m; i++){
		int x, y, z;
		cin>>x>>y>>z;
		x--; y--;
		g[x].push_back({y, z});
		g[y].push_back({x, z});
	}
	mint c1=1, c2=1;
	bool dame=0;
	vector<int> w;
	ll val=-1;
	auto dfs=[&](auto dfs, int x)->void{
		w.push_back(x);
		for(auto q:g[x]){
			int y=q.first;
			if(p[y]==0){
				p[y]=-p[x];
				v[y]=q.second-v[x];
				dfs(dfs, y);
			}else if(p[y]!=p[x]){
				if(v[y]!=q.second-v[x]){
					dame=1;
				}
			}else{
				ll v1=(q.second-v[x]-v[y])*p[x];
				if(v1%2!=0 || v1<=0 || (val!=-1 && val!=v1/2)){
					dame=1;
				}
				val=v1/2;
			}
		}
	};
	for(int i=0; i<n; i++){
		if(p[i]!=0) continue;
		p[i]=1;
		w.clear();
		val=-1;
		dfs(dfs, i);
		if(dame){
			cout<<0<<endl;
			return 0;
		}
		if(val==-1){
			ll l=1, r=k;
			for(auto x:w){
				if(p[x]==1){
					l=max(l, 1-v[x]);
					r=min(r, k-v[x]);
				}else{
					l=max(l, v[x]-k);
					r=min(r, v[x]-1);
				}
			}
			c1*=mint(max(0ll, r-l+1));
			l=1, r=k-1;
			for(auto x:w){
				if(p[x]==1){
					l=max(l, 1-v[x]);
					r=min(r, k-1-v[x]);
				}else{
					l=max(l, v[x]-(k-1));
					r=min(r, v[x]-1);
				}
			}
			c2*=mint(max(0ll, r-l+1));
		}else{
			for(auto x:w){
				if(p[x]==1) v[x]+=val;
				else v[x]-=val;
				if(v[x]<=0){
					c1=0, c2=0;
				}else if(v[x]==k){
					c2=0;
				}else if(v[x]>k){
					c1=0, c2=0;
				}
			}
		}
	}
	if(dame) cout<<0<<endl;
	else cout<<(c1-c2).val()<<endl;
    return 0;
}