#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++) #define per(x, s, t) for(llint (x) = (s); (x) >= (t); (x)--) #define reps(x, s) for(llint (x) = 0; (x) < (llint)(s).size(); (x)++) #define chmin(x, y) (x) = min((x), (y)) #define chmax(x, y) (x) = max((x), (y)) #define sz(x) ((ll)(x).size()) #define ceil(x, y) (((x)+(y)-1) / (y)) #define all(x) (x).begin(),(x).end() #define outl(...) dump_func(__VA_ARGS__) #define inf 1e18 using namespace std; typedef long long llint; typedef long long ll; typedef pair P; struct edge{ ll to, cost; edge(){} edge(ll a, ll b){ to = a, cost = b;} }; const ll dx[] = {1, 0, -1, 0}, dy[] = {0, -1, 0, 1}; const ll mod = 1000000007; //const ll mod = 998244353; struct mint{ ll x = 0; mint(ll y = 0){x = y; if(x < 0 || x >= mod) x = (x%mod+mod)%mod;} mint(const mint &ope) {x = ope.x;} mint operator-(){return mint(-x);} mint operator+(const mint &ope){return mint(x) += ope;} mint operator-(const mint &ope){return mint(x) -= ope;} mint operator*(const mint &ope){return mint(x) *= ope;} mint operator/(const mint &ope){return mint(x) /= ope;} mint& operator+=(const mint &ope){ x += ope.x; if(x >= mod) x -= mod; return *this; } mint& operator-=(const mint &ope){ x += mod - ope.x; if(x >= mod) x -= mod; return *this; } mint& operator*=(const mint &ope){ x *= ope.x, x %= mod; return *this; } mint& operator/=(const mint &ope){ ll n = mod-2; mint mul = ope; while(n){ if(n & 1) *this *= mul; mul *= mul; n >>= 1; } return *this; } mint inverse(){return mint(1) / *this;} bool operator ==(const mint &ope){return x == ope.x;} bool operator !=(const mint &ope){return x != ope.x;} }; mint modpow(mint a, ll n){ if(n == 0) return mint(1); if(n % 2) return a * modpow(a, n-1); else return modpow(a*a, n/2); } istream& operator >>(istream &is, mint &ope){ ll t; is >> t, ope.x = t; return is; } ostream& operator <<(ostream &os, mint &ope){return os << ope.x;} ostream& operator <<(ostream &os, const mint &ope){return os << ope.x;} bool exceed(ll x, ll y, ll m){return x >= m / y + 1;} void mark(){ cout << "*" << endl; } void yes(){ cout << "YES" << endl; } void no(){ cout << "NO" << endl; } ll sgn(ll x){ if(x > 0) return 1; if(x < 0) return -1; return 0;} ll gcd(ll a, ll b){if(b == 0) return a; return gcd(b, a%b);} ll lcm(ll a, ll b){return a/gcd(a, b)*b;} ll digitnum(ll x, ll b = 10){ll ret = 0; for(; x; x /= b) ret++; return ret;} ll digitsum(ll x, ll b = 10){ll ret = 0; for(; x; x /= b) ret += x % b; return ret;} string lltos(ll x){string ret; for(;x;x/=10) ret += x % 10 + '0'; reverse(ret.begin(), ret.end()); return ret;} ll stoll(string &s){ll ret = 0; for(auto c : s) ret *= 10, ret += c - '0'; return ret;} template void uniq(T &vec){ sort(vec.begin(), vec.end()); vec.erase(unique(vec.begin(), vec.end()), vec.end());} template ostream& operator << (ostream& os, vector& vec) { for(int i = 0; i < vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : " "); return os; } template ostream& operator << (ostream& os, deque& deq) { for(int i = 0; i < deq.size(); i++) os << deq[i] << (i + 1 == deq.size() ? "" : " "); return os; } template ostream& operator << (ostream& os, pair& pair_var) { os << "(" << pair_var.first << ", " << pair_var.second << ")"; return os; } template ostream& operator << (ostream& os, const pair& pair_var) { os << "(" << pair_var.first << ", " << pair_var.second << ")"; return os; } template ostream& operator << (ostream& os, map& map_var) { for(typename map::iterator itr = map_var.begin(); itr != map_var.end(); itr++) { os << "(" << itr->first << ", " << itr->second << ")"; itr++; if(itr != map_var.end()) os << ","; itr--; } return os; } template ostream& operator << (ostream& os, set& set_var) { for(typename set::iterator itr = set_var.begin(); itr != set_var.end(); itr++) { os << *itr; ++itr; if(itr != set_var.end()) os << " "; itr--; } return os; } template ostream& operator << (ostream& os, multiset& set_var) { for(typename multiset::iterator itr = set_var.begin(); itr != set_var.end(); itr++) { os << *itr; ++itr; if(itr != set_var.end()) os << " "; itr--; } return os; } template void outa(T a[], ll s, ll t){ for(ll i = s; i <= t; i++){ cout << a[i]; if(i < t) cout << " ";} cout << endl; } void dump_func() {cout << endl;} template void dump_func(Head &&head, Tail &&... tail) { cout << head; if(sizeof...(Tail) > 0) cout << " "; dump_func(std::move(tail)...); } struct UnionFind{ int size; vector parent; vector rank; vector v, e; UnionFind(){} UnionFind(int size){ this->size = size; parent.resize(size+1); rank.resize(size+1); v.resize(size+1); e.resize(size+1); init(); } void init(){ for(int i = 0; i <= size; i++){ parent[i] = i, rank[i] = 0; v[i] = 1, e[i] = 0; } } int root(int i){ if(parent[i] == i) return i; return parent[i] = root(parent[i]); } bool same(int i, int j){ return root(i) == root(j); } void merge(int i, int j){ // j will become new root parent[i] = j; v[j] += v[i]; e[j] += e[i] + 1; } void unite(int i, int j){ int root_i = root(i), root_j = root(j); if(root_i == root_j){ e[root_i]++; return; } if(rank[root_i] < rank[root_j]) merge(root_i, root_j); else merge(root_j, root_i); if(rank[root_i] == rank[root_j]) rank[root_i]++; } }; ll n, m, k; ll x[100005], y[100005], z[100005]; vector G[100005]; UnionFind uf(100005); ll lb[100005], ub[100005]; ll LB[100005], UB[100005]; ll a[100005], b[100005]; void dfs(int v, int p) { for(auto e : G[v]){ ll u = e.to; if(u == p) continue; a[u] = -a[v]; b[u] = e.cost - b[v]; dfs(u, v); } } mint calc(ll k) { rep(i, 1, n) if(uf.root(i) == i) LB[i] = lb[i], UB[i] = ub[i]; rep(i, 1, n){ ll r = uf.root(i); if(a[i] == 1) chmax(LB[r], 1-b[i]), chmin(UB[r], k-b[i]); else chmax(LB[r], -k+b[i]), chmin(UB[r], -1+b[i]); } mint ret = mint(1); rep(i, 1, n) if(uf.root(i) == i) ret *= mint(max(0LL, UB[i]-LB[i]+1)); return ret; } int main(void) { ios::sync_with_stdio(0); cin.tie(0); cin >> n >> m >> k; rep(i, 1, m){ cin >> x[i] >> y[i] >> z[i]; if(uf.same(x[i], y[i])) continue; uf.unite(x[i], y[i]); G[x[i]].push_back(edge(y[i], z[i])); G[y[i]].push_back(edge(x[i], z[i])); } rep(i, 1, n){ if(uf.root(i) != i) continue; lb[i] = 1, ub[i] = k, a[i] = 1; dfs(i, -1); } rep(i, 1, m){ ll u = x[i], v = y[i], r = uf.root(u); if(a[u] == a[v]){ if(abs(z[i]-(b[u]+b[v]))%2){ outl(0); return 0; } ll c = (z[i]-(b[u]+b[v])) / (a[u]+a[v]); chmax(lb[r], c), chmin(ub[r], c); } else{ if(b[u]+b[v] != z[i]){ outl(0); return 0; } } } outl(calc(k) - calc(k-1)); return 0; }