#include <bits/stdc++.h>
using namespace std;
#define ll long long
vector<int> wyjmij(deque<int> &q, vector<bool> &odw) {
vector<int> w;
while (!q.empty() && w.size()<3) {
if (!odw[q.front()]) {
q.pop_front();
}
w.push_back(q.front());
q.pop_front();
}
for (int i = w.size()-1; i >= 0; i--) {
q.push_front(w[i]);
}
return w;
}
void pchnij(int v, vector<int> &o, vector<int> &x) {
if (o[v] != o[o[v]]) {
pchnij(o[v], o, x);
x[v] ^= x[o[v]];
o[v] = o[o[v]];
}
}
void lacz(int a, int b, vector<int> &o, vector<int> &r, vector<int> &x) {
pchnij(a, o, x);
pchnij(b, o, x);
int c = o[a], d = o[b];
if (c==d) {
return;
}
if (r[c] < r[d]) {
swap(c, d);
}
r[c] += r[d];
o[d] = c;
x[d] = x[a]^x[b]^1;
}
bool czy(int a, int b, vector<int> &o, vector<int> &x) {
pchnij(a, o, x);
pchnij(b, o, x);
return o[a] == o[b];
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<pair<int, int>> z (m+1);
for (int i = 1; i <= m; i++) {
cin >> z[i].first >> z[i].second;
}
vector<vector<int>> v (n);
for (int i = 1; i <= m; i++) {
v[z[i].first-1].push_back(i);
v[z[i].second%n].push_back(-i);
if (z[i].first > z[i].second) {
v[0].push_back(i);
}
}
for (int i = 0; i < n; i++) {
sort(v[i].begin(), v[i].end());
}
vector<bool> odw (m+1, 0);
deque<int> q;
vector<vector<int>> k;
int l = 0;
for (int i = 0; i < n; i++) {
bool b = 0;
for (int j : v[i]) {
if (j < 0) {
b = 1;
if (odw[-j] == 1) {
l--;
}
odw[-j] = 0;
}
else {
if (odw[j] == 0) {
l++;
}
odw[j] = 1;
q.push_back(j);
}
}
if (l < 2) {
cout << "impossible\n";
return 0;
}
if (b) {
k.push_back(wyjmij(q, odw));
}
}
vector<int> o (n, 0), r (n, 1), x (n, 0);
for (int i = 0; i < n; i++) {
o[i] = i;
}
for (auto a : k) {
if (a.size() == 2) {
if (czy(a[0], a[1], o, x)) {
if (x[a[0]]^x[a[0]]^1) {
cout << "impossible\n";
return 0;
}
}
else {
lacz(a[0], a[1], o, r, x);
}
}
}
for (auto a : k) {
if (a.size() == 3) {
pchnij(a[0], o, x);
pchnij(a[1], o, x);
pchnij(a[2], o, x);
if (((o[a[0]] == o[a[1]]) && (x[a[0]]^x[a[1]])) || (o[a[0]] != o[a[1]])) {
lacz(a[0], a[1], o, r, x);
}
else if (((o[a[2]] == o[a[1]]) && (x[a[2]]^x[a[1]])) || (o[a[2]] != o[a[1]])) {
lacz(a[2], a[1], o, r, x);
}
else {
lacz(a[0], a[2], o, r, x);
}
}
}
for (int i = 1; i <= m; i++) {
pchnij(i, o, x);
cout << x[i];
}
cout << '\n';
}
