#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n, m, P;
ll QPow(ll a, ll b) {
	ll res = 1;
	for (; b; b >>= 1, a = a * a % P) if (b & 1) res = res * a % P;
	return res; 
}
int opC;
string ope;
struct Edge {
	int v, nxt;
} e[2005];
ll w[1005];
int head[505], len = 1, dep[505], prt[505], pid[505];
void Insert(int u, int v) {
	e[++len] = { v, head[u] };
	head[u] = len;
}
bool onT[1005];
int tE[505], tC;
namespace T {
	struct Edge {
		int v, nxt, x, y;
	} e[2005];
	int head[1005], len, fa[1005];
	void Init() {
		for (int i = 1; i <= m; i++) fa[i] = i;
	}
	int F(int u) { return fa[u] == u ? u : fa[u] = F(fa[u]); }
	void Insert(int u, int v) {
		e[++len] = { v, head[u] };
		head[u] = len;
	}
	void InsertD(int u, int v) {
		if (F(u) == F(v)) return;
		Insert(u, v), Insert(v, u);
		fa[F(u)] = F(v);
	}
	void Oper(int u, int v, ll w) {
		if (!onT[u]) {
			swap(u, v), w = (P - w) % P;
		}
		::w[v] = (::w[v] - w + P) % P;
		::w[u] = (::w[u] + w + P) % P;
		opC++;
		ope += to_string((P - w % P) % P) + " ";
		for (int i = 1; i <= tC; i++) ope += to_string(tE[i]) + " \n"[i == tC];
		opC++;
		ope += to_string(w % P) + " ";
		for (int i = 1; i <= tC; i++) ope += to_string(tE[i] == u ? v : tE[i]) + " \n"[i == tC];
	}
	bool vis[1005];
	ll sw;
	int se;
	void DFS1(int u, int fa) {
		vis[u] = true;
		(se += onT[u]) % P;
		(sw += w[u]) %= P;
		for (int i = head[u]; i; i = e[i].nxt) {
			int v = e[i].v;
			if (v == fa) continue;
			DFS1(v, u);
		}
	}
	void DFS2(int u, int fa) {
		vis[u] = true;
		for (int i = head[u]; i; i = e[i].nxt) {
			int v = e[i].v;
			if (v == fa) continue;
			DFS2(v, u);
			Oper(u, v, w[v]);
		}
	}
	void Solve() {
		ll opw = -1;
		for (int i = 1; i <= m; i++) {
			if (!vis[i]) {
				sw = se = 0;
				DFS1(i, 0);
				if (!se && !sw) continue;
				ll cw = sw * QPow(se, P - 2) % P;
				if (opw == -1) opw = cw;
				else if (opw != cw) return puts("-1"), void();
			}
		}
		if (opw >= 0) {
			opC++;
			for (int i = 1; i <= tC; i++) w[tE[i]] = (w[tE[i]] - opw % P + P) % P;
			ope += to_string(opw) + " ";
			for (int i = 1; i <= tC; i++) ope += to_string(tE[i]) + " \n"[i == tC];
		}
		memset(vis, 0, sizeof(vis));
		for (int i = 1; i <= m; i++) {
			if (!vis[i]) {
				DFS2(i, 0);
				if (w[i]) {
					puts("-1");
					return;
				}
			}
		}
		printf("%d\n%s", opC, ope.c_str());
	}
}
bool vis[505];
void AddE(int u, int v, int x) {
	while (u != v) {
		if (dep[u] < dep[v]) swap(u, v);
		T::InsertD(pid[u], x);
		u = prt[u];
	}
}
void DFS(int u, int f) {
	vis[u] = true;
	for (int i = head[u]; i; i = e[i].nxt) {
		if (i == (f ^ 1)) continue;
		int v = e[i].v;
		if (vis[v]) AddE(u, v, i >> 1);
		else {
			tE[++tC] = (i >> 1);
			dep[v] = dep[u] + 1;
			prt[v] = u, pid[v] = i >> 1;
			onT[i >> 1] = true;
			DFS(v, i);
		}
	}
}
int main() {
	scanf("%d%d%d", &n, &m, &P);
	T::Init();
	for (int i = 1, u, v; i <= m; i++) {
		scanf("%d%d%lld", &u, &v, w + i);
		Insert(u, v), Insert(v, u);
	}
	DFS(1, 0);
	T::Solve();
	return 0;
}