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#include <bits/stdc++.h>
using namespace std;
struct Clause {
int firstVar;
int secondVar;
};
struct Vertex {
int index;
int lowLink;
bool onStack;
};
struct TwoSatisfiability {
int numVars;
int x;
vector<Clause> clauses;
stack<int> st;
vector<Vertex> vertices;
vector<vector<int> > adj;
TwoSatisfiability(int n, int m) :
numVars(n),
clauses(m),
x(0),
vertices(n * 2, {-1, -1, false}),
adj(n * 2, vector<int>())
{
}
// bool tarjan(int &x, int i, vector<int> &result) {
bool tarjan(int i, vector<int> &result) {
Vertex &v = vertices[i];
v.index = x;
v.lowLink = x;
v.onStack = true;
st.push(i);
x++;
for (int a : adj[i]) {
Vertex &w = vertices[a];
if (w.index == -1) {
if (!tarjan(a, result)) return false;
v.lowLink = min(v.lowLink, w.lowLink);
} else if (w.onStack) {
v.lowLink = min(v.lowLink, w.index);
}
}
// is a SCC root node
if (v.lowLink == v.index) {
for (;;) {
int i = st.top();
int iv = inv(i);
if (vertices[iv].index == v.index) return false;
st.pop();
if (i < numVars) {
if (result[i] == -1)
result[i] = 1;
} else {
if (result[iv] == -1)
result[iv] = 0;
}
vertices[i].onStack = false;
if (vertices[i].index == v.index) {
break;
}
}
}
return true;
}
inline int idx(int v) { return (v > 0 ? (v - 1) : (numVars - v - 1)); }
inline int inv(int i) { return i + ((i < numVars) ? numVars : -numVars); }
bool isSatisfiable(vector<int>& result) {
// construct the implication graph (l1 l2) -> !l1 ->l2 !l2->l1
for(Clause clause : clauses) {
adj[idx(-clause.firstVar)].push_back(idx(clause.secondVar));
adj[idx(-clause.secondVar)].push_back(idx(clause.firstVar));
}
// find SCC's of graph
// int x = 0;
for (int i = 0; i < vertices.size(); i++) {
Vertex &v = vertices[i];
if (v.index == -1) {
if (!tarjan(i, result)) return false;
}
}
return true;
}
};
int main() {
ios::sync_with_stdio(false);
int n, m;
cin >> n >> m;
TwoSatisfiability twoSat(n, m);
for (int i = 0; i < m; ++i) {
cin >> twoSat.clauses[i].firstVar >> twoSat.clauses[i].secondVar;
}
vector<int> result(n, -1);
if (twoSat.isSatisfiable(result)) {
cout << "SATISFIABLE" << endl;
for (int i = 1; i <= n; ++i) {
if (result[i-1]) {
cout << i;
} else {
cout << -i;
}
if (i < n) {
cout << " ";
} else {
cout << endl;
}
}
} else {
cout << "UNSATISFIABLE" << endl;
}
return 0;
}
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