#define IA_PROB "2sat"
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
using namespace std;
typedef int node;
typedef list<node> node_list;
typedef vector<node_list> graph;
node neg(node x, int n) {
return (x + n) % (2 * n);
}
node int2node(int x, int n) {
return x > 0 ? x : neg(-x, n);
}
void dfs(graph &G, vector<bool> &seen, node_list &stack, node x)
{
seen[x] = true;
for (node_list::iterator i = G[x].begin(); i != G[x].end(); i++) {
if (!seen[*i]) {
dfs(G, seen, stack, *i);
}
}
stack.push_front(x);
}
int main()
{
freopen(IA_PROB".in", "r", stdin);
freopen(IA_PROB".out", "w", stdout);
int n, m;
scanf("%d %d", &n, &m);
graph G(2 * n, node_list()), Gr(2 * n, node_list());
for (int i = 0; i < m; i++) {
int x, y;
scanf("%d %d", &x, &y);
node a, b;
a = int2node(x, n);
b = int2node(y, n);
G[neg(a, n)].push_back(b);
G[neg(b, n)].push_back(a);
Gr[a].push_back(neg(b, n));
Gr[b].push_back(neg(a, n));
}
node_list topo_stack;
vector<bool> seen(2 * n, false);
for (int i = 1; i <= n; i++) {
if (!seen[i]) {
dfs(G, seen, topo_stack, i);
}
if (!seen[neg(i, n)]) {
dfs(G, seen, topo_stack, neg(i, n));
}
}
fill(seen.begin(), seen.end(), false);
/* dfs on the reversed graph, starting from nodes in topological order */
vector<node_list> sccs;
while (!topo_stack.empty()) {
node node = topo_stack.front();
topo_stack.pop_front();
if (!seen[node]) {
sccs.push_back(node_list());
dfs(Gr, seen, sccs.back(), node);
}
}
/* for every node, remember what scc it is part of */
vector<int> node2scc(2 * n, -1);
for (int scc = 0; scc < sccs.size(); scc++) {
for (node_list::iterator x = sccs[scc].begin(); x != sccs[scc].end(); x++) {
node2scc[*x] = scc;
if (node2scc[neg(*x, n)] == scc) {
printf("-1");
return 0;
}
}
}
/*
* Traversing the sccs in topo order, we start with an scc with no incoming edges (parents).
* By assigning 0 to it we don't impose any restriction on its children.
* The symmetric scc won't have any outgoing edges (children) and assigning 1 to it doesn't
* impose any restriction on its parents.
* This way we eliminate the current scc pair without any impact on the rest of the graph.
* We can just proceed recursively.
*/
vector<int> scc2res(sccs.size(), -1);
for (int scc = 0; scc < sccs.size(); scc++) {
if (scc2res[scc] == -1) {
int sym_scc = node2scc[neg(sccs[scc].front(), n)];
scc2res[scc] = 0;
scc2res[sym_scc] = 1;
}
}
for (node i = 1; i <= n; i++) {
printf("%d ", scc2res[node2scc[i]]);
}
return 0;
}