// bzoj3624#include<algorithm>#include<iostream>#include<cstdlib>#include<cstring>#include<cstdio>#include<cmath>#define LL long long#define inf 2147483640#define Pi acos(-1.0)#define free(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);using namespace std;const int maxn=20010,maxm=100010;struct edge {int u,v,w;}e[2][maxm],ans[maxm];int n,m,K,M[2],fa[maxn];int find(int x) {	return fa[x]==x ? x : fa[x]=find(fa[x]);}int main() {	scanf("%d%d%d",&n,&m,&K);	for (int u,v,w,i=1;i<=m;i++) {		scanf("%d%d%d",&u,&v,&w);		e[w][++M[w]]=(edge){u,v,w};	}	int cnt=0,s=0;	for (int i=1;i<=n;i++) fa[i]=i;	for (int i=1;i<=M[1];i++) {		int r1=find(e[1][i].u),r2=find(e[1][i].v);		if (r1!=r2) cnt++,fa[r1]=r2;	}	if (cnt<n-1) {		for (int i=1;i<=M[0];i++) {			int r1=find(e[0][i].u),r2=find(e[0][i].v);			if (r1!=r2) ans[++s]=e[0][i],cnt++,fa[r1]=r2;		}		if (cnt<n-1 || s>K) {puts("no solution");return 0;}	}	for (int i=1;i<=n;i++) fa[i]=i;	for (int i=1;i<=s;i++) fa[find(ans[i].u)]=find(ans[i].v);	for (int i=1;i<=M[0];i++) {		if (s==K) break;		int r1=find(e[0][i].u),r2=find(e[0][i].v);		if (r1!=r2) ans[++s]=e[0][i],fa[r1]=r2;	}	if (s<K) {puts("no solution");return 0;}	for (int i=1;i<=M[1];i++) {		int r1=find(e[1][i].u),r2=find(e[1][i].v);		if (r1!=r2) ans[++s]=e[1][i],fa[r1]=r2;	}	for (int i=1;i<=s;i++) printf("%d %d %d\n",ans[i].u,ans[i].v,ans[i].w);	return 0;}