rt

#include <bits/stdc++.h>
#define maxn 1000100
using namespace std;
//板子代码来自：https://www.luogu.com.cn/blog/85514/post-2-sat-xue-xi-bi-ji
//暴力第二种解法为数位dp的感觉
int dfn[maxn];
int low[maxn];
int cnt;
int tot;
int outdegree[maxn];
int num[maxn];
int s[maxn];
int top;
vector<int> G[maxn];
bool vis[maxn];
int belong[maxn];
int n, m;

void tarjan(int x) {
	int c;
	low[x] = dfn[x] = ++cnt;
	s[++top] = x;
	vis[x] = true;
	for (unsigned int i = 0; i < G[x].size(); i++) {
		c = G[x][i];
		if (!dfn[c]) {
			tarjan(c);
			low[x] = min(low[x], low[c]);
		} else if (!vis[c]) {
			low[x] = min(dfn[c], low[x]);
		}
	}
	if (dfn[x] == low[x]) {
		tot++;
		c = -1;
		while (x != c) {
			//TODO
			c = s[top--];
			belong[c] = tot;
			num[tot]++;
			vis[c] = false;
		}
	}
}

int i, j, a, b;
int main() {
	memset(vis, false, sizeof vis);
	cin >> n >> m;
	for (int k = 1; k <= m; k++) {
		cin >> i >> a >> j >> b;
		G[i + n * b].push_back(j + n * (b ^ 1));
		G[j + n * b].push_back(i + n * (a ^ 1));
//		G[i + (n & a)].push_back(j +)
	}
	for (i = 1; i <= 2 * n; i++)
		if (!dfn[i]) tarjan(i);
	for (i = 1; i <= n; i++) {
		if (belong[i] == belong[i + n]) {
			cout << "IMPOSSIBLE";
			return 0;
		}
	}
	cout << "POSSIBLE" << endl;
	for (i = 1; i <= n; i++) {
		if (belong[i] < belong[i + n])cout << "0 ";
		else cout << "1 ";
	}
	return 0;
}

验证码acp6寄