#include <bits/stdc++.h>
using namespace std;
#define For(Ti,Ta,Tb) for(auto Ti=(Ta);Ti<=(Tb);++Ti)
#define Dec(Ti,Ta,Tb) for(auto Ti=(Ta);Ti>=(Tb);--Ti)
#define debug(...) fprintf(stderr,__VA_ARGS__)
#define range(Tx) begin(Tx),end(Tx)
using ll=long long;
ll power(ll x,ll y,ll mod){
	ll r=1;
	for(;y;y>>=1,x=x*x%mod){
		if(y&1) r=r*x%mod;
	}
	return r;
}
const int N=505,M=1005;
int n,m,p,fa[N],fai[N],dep[N],vis[N],in_tree[M],vis2[M];
struct Edge{
	int u,v,x;
}edge[M];
vector<pair<int,int>> g[N],e[N],g2[N];
void dfs(int u){
	for(auto [v,i]:g[u]){
		if(!vis[v]){
			vis[v]=1;
			fa[v]=u;
			fai[v]=i;
			dep[v]=dep[u]+1;
			e[u].emplace_back(v,i);
			e[v].emplace_back(u,i);
			in_tree[i]=1;
			dfs(v);
		}
	}
}
struct DSU{
	int fa[M];
	int find(int u){
		return u==fa[u]?u:fa[u]=find(fa[u]);
	}
}dsu;
pair<int,int> exc[M];
int ans[M];
void get_sum(int u,int fa,int& sum,int& cnt){
	(sum+=edge[u].x)%=p;
	cnt+=in_tree[u];
	for(auto [v,i]:g2[u]){
		if(v!=fa){
			get_sum(v,u,sum,cnt);
		}
	}
}
void dfs2(int u,int fa,int fai){
	vis2[u]=1;
	for(auto [v,i]:g2[u]){
		if(v!=fa){
			dfs2(v,u,i);
		}
	}
	if(edge[u].x){
		assert(fa);
		auto [x,y]=exc[fai];
		if(u==x){
			(ans[1]+=edge[u].x)%=p;
			(ans[fai]+=-edge[u].x+p)%=p;
			(edge[fa].x+=edge[u].x)%=p;
			edge[u].x=0;
		}else{
			(ans[1]+=-edge[u].x+p)%=p;
			(ans[fai]+=edge[u].x)%=p;
			(edge[fa].x+=edge[u].x)%=p;
			edge[u].x=0;
		}
	}
}
int main(){
	cin.tie(nullptr)->sync_with_stdio(false);
	cin>>n>>m>>p;
	For(i,1,m){
		cin>>edge[i].u>>edge[i].v>>edge[i].x;
		g[edge[i].u].emplace_back(edge[i].v,i);
		g[edge[i].v].emplace_back(edge[i].u,i);
	}
	dfs(1);
	iota(dsu.fa+1,dsu.fa+m+1,1);
	int tot=0;
	exc[++tot]={0,0};
	For(i,1,m){
		if(!in_tree[i]){
			auto& [u,v,x]=edge[i];
			if(dep[u]<dep[v]){
				swap(u,v);
			}
			for(int x=u;x!=v;x=fa[x]){
				if(dsu.find(i)!=dsu.find(fai[x])){
					exc[++tot]={fai[x],i};
					g2[i].emplace_back(fai[x],tot);
					g2[fai[x]].emplace_back(i,tot);
					dsu.fa[dsu.find(i)]=dsu.find(fai[x]);
				}
			}
		}
	}
	{
		int sum=0,cnt=0;
		get_sum(1,0,sum,cnt);
		int x=1LL*sum*power(cnt,p-2,p)%p;
		ans[1]=x;
		For(i,1,m){
			if(in_tree[i]){
				(edge[i].x+=-x+p)%=p;
			}
		}
	}
	For(i,1,m){
		int sum=0,cnt=0;
		get_sum(i,0,sum,cnt);
		if(sum){
			cout<<"-1\n";
			return 0;
		}
	}
	For(i,1,m){
		if(vis2[i]) continue;
		dfs2(i,0,0);
	}
	cout<<tot<<'\n';
	For(i,1,tot){
		cout<<ans[i]<<' ';
		For(j,1,m){
			if(in_tree[j]&&j!=exc[i].first){
				cout<<j<<' ';
			}
		}
		if(exc[i].second){
			cout<<exc[i].second;
		}
		cout<<'\n';
	}
	return 0;
}