#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define ff first
#define ss second
#define MOD 1000000007
#define INF 1000000019
#define POT (1<<20)
#define INFL 1000000000000000099LL
ll n,m,a,b,c;
vector<pair<ll,ll>>kon[100007];
ll nxt[100007],pop[100007],co[100007];
vector<ll>v[100007];
void st(ll x,ll y){
co[x]=y;
for(ll i : v[x])st(i,y^1);
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>m;
for(ll i=0;i<n;i++){
nxt[i]=(i+1)%n;
pop[i]=(i+n-1)%n;
}
for(ll i=0;i<m;i++){
co[i]=-1;
cin>>a>>b;
a--;
b%=n;
if(b<=a)b+=n;
kon[a].pb({b,i});
}
ll akbst=0;
ll kto=-1;
bool bl=1;
while(bl){
bl=0;
for(ll i=0;i<n;i++){
//cout<<i<<" "<<flush;
//for(ll j=0;j<n;j++){
// cout<<"\n";
// cout<<pop[j]<<" "<<nxt[j]<<" ";
// for(auto k: kon[j])cout<<k.ff<<" ";
// cout<<"\n";
//}
//cout<<kon[i].size()<<" ";
//cout<<"\n\n";
//cout<<flush;
sort(kon[i].begin(),kon[i].end());
reverse(kon[i].begin(),kon[i].end());
vector<pair<ll,ll>>pom;
bool bl2=0;
for(auto j : kon[i]){
//cout<<akbst<<" "<<kto<<" "<<j.ff<<" "<<j.ss<<"\n";
if(j.ff<=akbst){
//cout<<j.ff<<" "<<akbst<<flush;
bl=1;
// co[j.ss]=kto;
v[kto].pb(j.ss);
ll idx=nxt[i];
while(idx<=j.ff){
for(auto k : kon[idx])pom.pb(k);
kon[idx].clear();
nxt[pop[idx]]=nxt[idx];
pop[nxt[idx]]=pop[idx];
if(idx==nxt[idx]){
for(ll i=0;i<m;i++){
if(co[i]==-1)st(i,1);
}
for(ll i=0;i<m;i++)cout<<co[i];
return 0;
}
idx=nxt[idx];
}
}
else{
bl2=1;
kto=j.ss;
akbst=j.ff;
}
}
if(kon[i].size()){
kon[i]={kon[i][0]};
if(bl2==0)kon[i].pop_back();
}
for(auto k : pom)kon[i].pb(k);
if(pom.size()){
i--;
continue;
}
}
akbst-=n;
}
//cout<<"\n\n\n";
for(ll i=0;i<n;i++){
//cout<<i<<": ";
//for(auto j : kon[i])cout<<j.ff<<" ";
//cout<<"\n"<<flush;
}
ll idx=0;
for(idx;kon[idx].empty();idx++);
ll ak=idx;
while(1){
//cout<<ak<<" "<<kon[ak][0].ss<<" "<<flush;
ll zas=kon[ak][0].ff;
st(kon[ak][0].ss,0);
kon[ak].clear();
if(zas-n>=idx)break;
ll i;
for(i=zas;i>ak;i--){
if(kon[i%n].size())break;
}
if(i==ak){
cout<<"impossible";return 0;
}
ak=i;
}
idx=0;
bl=0;
for(ll i=0;i<n;i++)bl|=(bool)(kon[i].size());
if(bl==0){
cout<<"impossible";return 0;
}
for(idx;kon[idx].empty();idx++);
ak=idx;
while(1){
ll zas=kon[ak][0].ff;
st(kon[ak][0].ss,1);
kon[ak].clear();
if(zas-n>=idx)break;
ll i;
for(i=zas;i>ak;i--){
if(kon[i%n].size())break;
}
if(i==ak){
cout<<"impossible";return 0;
}
ak=i;
}
for(ll i=0;i<m;i++)cout<<co[i];
}
