#include<bits/stdc++.h>
using namespace std;
#define X first
#define Y second
using pii = pair<int,int>;
#define vt vector
#define pb push_back
#define f0r(i,a,b) for(auto i =(a);i!=(b);i++)
#define r0f(i,a,b) for(auto i=(a);i>=(b);i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
//sim dor ris enix rge range dud debug 2enix 2dor imie
#define sim template<class c
#define dor > debug& operator<<
#define ris return *this
#define eni(x) sim> typename \
enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i)
sim> struct rge { c b,e; };
sim> rge<c> range(c i, c j) {
return rge<c>{i,j};
}
sim> auto dud(c* x) -> decltype(cout << *x, 0);
sim> char dud(...);
struct debug {
~debug() { cerr << endl; }
eni(!=) { cerr << boolalpha << i; ris; }
eni(==) { ris << range(all(i)); }
sim, class b dor(pair<b,c> d) {
ris << "(" << d.X << ", " << d.Y << ")";
}
sim dor(rge<c> d) {
*this << "{";
f0r(i,d.b,d.e) *this << ", " + 2*(i==d.b) << *i;
ris << "}";
}
};
#define imie(r...) " [" << #r << ": " << (r) << "] "
signed main() {
cin.tie(0)->sync_with_stdio(0);
//try every subset
//M is number of ranges
//N is L
int L,N; cin >> L >> N;
vt<pii> ro (N);
f0r(i,0,N) cin >> ro[i].X >> ro[i].Y, ro[i].X--, ro[i].Y--;
f0r(msk,0,(1<<N)) {
vt<int> as (L), bs(L);
auto mark = [L](vt<int> &a, int l, int r) {
if(r < l) {
f0r(i,l,L) a[i] = 1;
f0r(i,0,r+1) a[i] = 1;
} else {
f0r(i,l,r+1) a[i] = 1;
}
};
string res;
f0r(g,0,N) {
res += (msk & (1 << g)) ? '1' : '0';
mark((msk & (1<<g)) ? as : bs, ro[g].X, ro[g].Y);
}
bool ok = 1;
f0r(i,0,L) if(not as[i] or not bs[i]) ok = 0;
if(ok) {
cout << res << '\n';
exit(0);
}
}
cout << "impossible\n";
}
