#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn5 = 5e3 + 10;
int a[maxn5], b[maxn5];
bool av[2][maxn5];
int main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
int n, m; cin >> n >> m;
for(int i = 0; i < m; i++){
cin >> a[i] >> b[i];
a[i]--;
b[i]--;
}
for(int mask = 1; mask < (1 << m) - 1; mask++){
memset(av, false, sizeof av);
for(int i = 0; i < m; i++){
int x = a[i];
while(true){
av[(mask >> i)&1][x] = true;
if(x == b[i])
break;
x++;
if(x == n)
x = 0;
}
}
bool re = true;
for(int i = 0; i < n; i++)
if(!av[0][i] || !av[1][i])
re = false;
if(re){
for(int i = 0; i < m; i++)
cout << ((mask >> i)&1);
return cout << endl, 0;
}
}
cout << "impossible" << endl;
}
