#include <bits/stdc++.h>
#define int long long
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
using namespace std;
signed main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n,m; cin >> n >> m;
vector<pair<pair<int,int>,int>> edge1(m);
vector<pair<pair<int,int>,int>> edge(m);
vector<bool> c(m);
vector<pair<int,int>> furthest(n+1, {-1,-1});
for (int i = 0; i < m; i++)
{
int a,b; cin >> a >> b;
if(b<a) b+=n;
edge[i]={{a,b},i};
}
sort(all(edge));
bool b=false;
for (int x = 0; x < (1<<m); x++)
{
bool b2=true;
int e=-100;
int s=-1;
int e2=-100;
int s2=-1;
for (int j = 0; j < m; j++) c[j]=(bool)(x&(1<<j));
for (int i = 0; i < m; i++)
{
if(c[edge[i].second]==1) {
if(s==-1) { s=edge[i].first.first; e=edge[i].first.second; }
else if(e>=edge[i].first.first-1) e=edge[i].first.second;
}
}
for (int i = 0; i < m; i++)
{
if(c[edge[i].second]==0) {
if(s2==-1) { s2=edge[i].first.first; e2=edge[i].first.second; }
else if(e2>=edge[i].first.first-1) e2=edge[i].first.second;
}
}
if(e>=s+n-1&&e2>=s2+n-1) b2=true;
else b2=false;
if(b2){
for (int i = 0; i < m; i++)
{
cout << c[i];
}
b=true;
break;
}
}
if(b==false) cout << "impossible\n";
return 0;
}
