#include<cstdio>
#include<cstdlib>
#include<ctime>
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;

const int NMAX = 1010;
const int MMAX = 10010;

int N, M;
int Bl[MMAX][4];
int val[NMAX];
vector<int> rel[NMAX];

void citire()
{
	cin >> N >> M;
	for(int i = 1 ; i <= M ; i++)
	{
		cin >> Bl[i][1] >> Bl[i][2] >> Bl[i][0];
		rel[Bl[i][1]].push_back(i);
		rel[Bl[i][2]].push_back(i);
	}
	fill(val + 1 , val + N + 1, 1);
}

inline void aleator(int i)
{
	int x = rand() % 2 + 1;
	val[Bl[i][x]] = !val[Bl[i][x]];
}

bool satisfactie(int x)
{
	for(int i = 0 ; i < rel[x].size() ; i++)
		switch(Bl[rel[x][i]][0])
		{
		case 0:
			if(!val[Bl[rel[x][i]][1]] && !val[Bl[rel[x][i]][2]])
			{
				int al = rand() % 2 + 1;
				val[Bl[rel[x][i]][al]] = !val[Bl[rel[x][i]][al]];
				return Bl[rel[x][i]][al];
			}
		case 1:
			if(!val[Bl[rel[x][i]][1]] && val[Bl[rel[x][i]][2]])
			{
				int al = rand() % 2 + 1;
				val[Bl[rel[x][i]][al]] = !val[Bl[rel[x][i]][al]];
				return Bl[rel[x][i]][al];
			}
		case 2:
			if(val[Bl[rel[x][i]][1]] && !val[Bl[rel[x][i]][2]])
			{
				int al = rand() % 2 + 1;
				val[Bl[rel[x][i]][al]] = !val[Bl[rel[x][i]][al]];
				return Bl[rel[x][i]][al];
			}
		case 3:
			if(val[Bl[rel[x][i]][1]] && val[Bl[rel[x][i]][2]])
			{
				int al = rand() % 2 + 1;
				val[Bl[rel[x][i]][al]] = !val[Bl[rel[x][i]][al]];
				return Bl[rel[x][i]][al];
			}
		}
	return 0;
}

void scriere()
{
	int NR = 0;
	for(int i = 1 ; i <= N ; i++)
		if(val[i])
			NR++;
	printf("%d\n", NR);
	for(int i = 1 ; i <= N ; i++)
		if(val[i])
			printf("%d\n", val[i]);
}

int main()
{
	freopen("party.in", "r", stdin);
	freopen("party.out", "w", stdout);
	citire();
	srand(time(NULL));
	int x = 1, k;
	while(x)
	{
		k = satisfactie(x);
		x = k;
	}
	scriere();
	return 0;
}