#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;
struct node {
node* left;
node* right;
int sumMIN=0;
int sum=0;
int sumMAX=0;
int lazy=0;
int mnI=0;
void update(){
sumMIN=min(left->sumMIN,right->sumMIN);
sumMAX=max(left->sumMAX,right->sumMAX);
sum=left->sum+right->sum;
if(left->sumMIN<=right->sumMIN) mnI=left->mnI;
else mnI=right->mnI;
}
};
struct segtree {
int n;
node* root=new node{nullptr,nullptr,0,0,0,0};
void propagate(node* x){
x->left->lazy+=x->lazy;
x->right->lazy+=x->lazy;
x->left->sum+=x->lazy;
x->right->sum+=x->lazy;
x->left->sumMIN+=x->lazy;
x->right->sumMIN+=x->lazy;
x->left->sumMAX+=x->lazy;
x->right->sumMAX+=x->lazy;
x->lazy=0;
}
void update(node* x, int l, int r, int qL, int qR, int v){
if(l>qR||r<qL) return;
if(l>=qL&&r<=qR){
x->lazy+=v;
x->sumMAX+=v;
x->sumMIN+=v;
x->sum+=v;
return;
}
propagate(x);
int mid=(l+r)/2;
update(x->left,l,mid,qL,qR,v);
update(x->right,mid+1,r,qL,qR,v);
x->update();
}
void build(node* x, int l, int r){
if(l==r){
x->sumMIN=0;
x->sumMAX=0;
x->sum=0;
x->mnI=l;
return;
}
int mid=(l+r)/2;
x->left=new node{nullptr,nullptr,0,(long long)0,0,0};
x->right=new node{nullptr,nullptr,0,(long long)0,0,0};
build(x->left,l,mid);
build(x->right,mid+1,r);
x->update();
}
int queryMAX(node* x, int l, int r, int qL, int qR){
if(qR<l||r<qL) return -1e9;
if(l>=qL&&r<=qR){
return x->sumMAX;
}
propagate(x);
int mid=(l+r)/2;
int qs=max(queryMAX(x->left,l,mid,qL,qR),queryMAX(x->right,mid+1,r,qL,qR));
return qs;
}
int queryMIN(node* x, int l, int r, int qL, int qR){
if(qR<l||r<qL) return 1e9;
if(l>=qL&&r<=qR){
return x->sumMIN;
}
propagate(x);
int mid=(l+r)/2;
int q1=queryMIN(x->left,l,mid,qL,qR);
int q2=queryMIN(x->right,mid+1,r,qL,qR);
return min(q1,q2);
}
void update(int l, int r, int v){
update(root,0,n-1,l,r,v);
}
int queryMAX(int l, int r){
return queryMAX(root,0,n-1,l,r);
}
int queryMIN(int l, int r){
return queryMIN(root,0,n-1,l,r);
}
segtree(int x){
n=x;
build(root,0,n-1);
}
};
signed main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n,m; cin >> n >> m;
segtree rem(n);
vector<pair<int,int>> edge(m);
for (int i = 0; i < m; i++)
{
int a,b; cin >> a >> b; a--; b--;
edge[i]={a,b};
if(a<=b){
rem.update(a,b,1);
}else{
rem.update(a,n-1,1);
rem.update(0,b,1);
}
}
if(rem.queryMIN(0,n-1)<2) { cout << "impossible\n"; return 0; }
vector<int> out(n,0);
for (int i = 0; i < m; i++)
{
int a=edge[i].first,b=edge[i].second;
int q=0;
if(a<=b){
q=rem.queryMIN(a,b);
}else{
q=min(rem.queryMIN(a,n-1),rem.queryMIN(0,b));
}
if(q<=1) continue;
else{
if(a<=b){
rem.update(a,b,-1);
}else{
rem.update(a,n-1,-1);
rem.update(0,b,-1);
}
out[i]=1;
}
}
for (int i = 0; i < m; i++) cout << out[i];
cout << "\n";
return 0;
}
