#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int N=2e4+5, M=1e5+5;typedef long long ll;inline int read(){    char c=getchar();int x=0,f=1;    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();}    while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();}    return x*f;}int n, m, k, u, v, c, m0, m1, p;struct meow{int u, v, c;}a[M], b[M], ans[N];int fa[N];int find(int x) {return x==fa[x] ? x : fa[x]=find(fa[x]);}int flag[N];int main() {    freopen("in","r",stdin);    n=read(); m=read(); k=read();    for(int i=1; i<=m; i++) {        u=read(), v=read(), c=read();        if(c==1) a[++m1]=(meow){u,v,c};        else b[++m0]=(meow){u,v,c};    }    int cnt=0;    for(int i=1; i<=n; i++) fa[i]=i;    for(int i=1; i<=m1; i++) {        u=a[i].u, v=a[i].v;        int x=find(u), y=find(v);        if(x==y) continue;        fa[x]=y;        if(++cnt == n-1) break;    }    for(int i=1; i<=m0; i++) {        u=b[i].u, v=b[i].v;        int x=find(u), y=find(v);        if(x==y) continue;        fa[x]=y; ans[++p]=b[i]; flag[i]=1;        if(++cnt == n-1) break;    }    if(p > k || cnt < n-1) {puts("no solution"); return 0;}    for(int i=1; i<=n; i++) fa[i]=i;    for(int i=1; i<=p; i++) fa[find(ans[i].u)] = find(ans[i].v);    cnt=p;    if(cnt<k) for(int i=1; i<=m0; i++) if(!flag[i]){        u=b[i].u, v=b[i].v;        int x=find(u), y=find(v);        if(x==y) continue;        fa[x]=y; ans[++cnt]=b[i];        if(cnt == k) break;    }    for(int i=1; i<=m1; i++) {        u=a[i].u, v=a[i].v;        int x=find(u), y=find(v);        if(x==y) continue;        fa[x]=y; ans[++cnt]=a[i];        if(cnt == n-1) break;    }    for(int i=1; i<=cnt; i++) printf("%d %d %d\n",ans[i].u, ans[i].v, ans[i].c);}