n, m = map(int, raw_input().split()) ans = [False for i in xrange(n)] query = sorted([map(int, raw_input().split()) for _ in xrange(m)]) used = [False for _ in xrange(n)] for i in xrange(m-1, -1, -1): a, b = query[i] if not used[b]: ans[a] = True used[a] = True #print ans print int(''.join(map(lambda x: '01'[x], reversed(ans))))