#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>
using ll = long long;
#define debug(x) #x << " = " << x << '\n'
int main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
std::ios_base::sync_with_stdio(false);
std::cin.tie(0);
int n, m;
std::cin >> n >> m;
std::vector<std::pair<int, int>> a(m);
for (auto &[l, r] : a) {
std::cin >> l >> r;
l--, r--;
}
for (int mask = 0; mask < (1 << m); mask++) {
std::vector<int> color(n, 0);
for (int i = 0; i < m; i++) {
auto [l, r] = a[i];
if (mask >> i & 1) {
if (l <= r) {
for (int j = l; j <= r; j++) {
color[j] |= 1;
}
} else {
for (int j = l; j < n; j++) {
color[j] |= 1;
}
for (int j = 0; j <= r; j++) {
color[j] |= 1;
}
}
} else {
if (l <= r) {
for (int j = l; j <= r; j++) {
color[j] |= 2;
}
} else {
for (int j = l; j < n; j++) {
color[j] |= 2;
}
for (int j = 0; j <= r; j++) {
color[j] |= 2;
}
}
}
}
bool ok = true;
for (int i = 0; i < n && ok; i++) {
if (color[i] != 3) {
ok = false;
}
}
if (ok) {
for (int i = 0; i < m; i++) {
std::cout << (mask >> i & 1);
}
return 0;
}
}
std::cout << "impossible";
return 0;
}
