Let us recall a well-known problem (also called a "bayan" in Russian). You are given an array $$$a_1, a_2, \ldots, a_n$$$ of integers. Answer the queries: given a segment $$$[l, r]$$$ ($$$1 \leq l \leq r \leq n$$$), check if there exist two equal elements among $$$a_l, a_{l+1}, \ldots, a_r$$$.
Please help to make good tests for this well-known problem! You are given two integers $$$n$$$, $$$m$$$, and also $$$2m$$$ different segments $$$[l_i, r_i]$$$. Find any array $$$a_1, a_2, \ldots, a_n$$$ such that, for exactly $$$m$$$ queries, the answer is positive, and for exactly $$$m$$$ queries, the answer is negative. You should report if there is no such array.
The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 10^5$$$) — the number of test cases. Description of test cases follows.
The first line of each test case contains two integers $$$n$$$, $$$m$$$ ($$$2 \leq n \leq 2 \cdot 10^5$$$, $$$1 \leq m \leq 10^5$$$).
Each of the next $$$2m$$$ lines contains two integers $$$l_i$$$, $$$r_i$$$ ($$$1 \leq l_i \leq r_i \leq n$$$) — the given segments. It is guaranteed that all segments are different.
It is guaranteed that the sum of $$$n$$$ for all test cases does not exceed $$$2 \cdot 10^5$$$ and the sum of $$$m$$$ for all test cases does not exceed $$$10^5$$$.
For each test case, print the answer to the problem.
If such an array $$$a$$$ exists, print $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 10^9$$$). Otherwise, print a single integer $$$-1$$$.
If there are several possible answers, print any one of them.
32 11 12 26 21 34 62 43 54 31 21 12 22 33 33 4
-1 1 2 3 3 2 1 5 5 5 5
