struct N{int i,j,w;};
vector<N>d[1d5];
int e[1d5];
int h[1d5];
int o[1d5];
int z[1d5];
int dir;
bool f(int i,int l,int g){
	if(e[i]==0){
		e[i]=1;
		h[i]=g;
		o[i]=l;
		rep(j,d[i].size()){
			z[l]=d[i][j].i;
			if(f(d[i][j].j,l+1,g+d[i][j].w)){
				if(e[i]==3){
					if(dir){
						rep(k,l,o[i]-1){
							wtSp(z[k]+1);
						}
						wt(z[o[i]-1]+1);
					}else{
						rrep(k,l+1,o[i]){
							wtSp(z[k]+1);
						}
						wt(z[l]);
					}
					exit(0);
				}
				return true;
			}
		}
		e[i]=2;
	}
	if(e[i]==1){
		if(g!=h[i]){
			wt(l-o[i]);
			wt(i+1);
			dir=g>h[i];
			o[i]=l;
			e[i]=3;
			return true;
		}
	}
	return false;
}
{
	int@n,@m,@(u,v,w)[m];
	rep(i,m){
		d[u[i]-1].push_back({i,v[i]-1,w[i]});
		d[v[i]-1].push_back({i,u[i]-1,-w[i]});
	}
	rep(i,n){
		f(i,0,0);
	}
	wt("-1");
}