This is a communication problem. Pay attention to its unusual constraints.
That was long ago, in a past forgotten by all of ECUST...
In that forgotten age, Zhulin and Qianwai fought side by side, lived together, and gazed up at the same stars. Later, sand buried their language, oceans severed their roads, and even their names faded from history. Only the vast, silent star chart above them remained: public, radiant, and unchanging. Yet nobody knew which stars they had once quietly joined into a message.
This problem has $$$20$$$ test cases.
You are given an undirected graph $$$G=(V,E)$$$ with $$$|V|=2000$$$ and $$$|E|=43\,600$$$. It has no multiple edges or self-loops and is generated as follows. Initially, $$$G$$$ has $$$|V|$$$ vertices and no edges. Then, $$$|E|$$$ times, the generator uniformly chooses one of the vertex pairs not yet joined by an edge and adds an undirected edge between them.
Your program will be run twice:
First run
In the first run, you play Zhulin. Choose and output $$$n$$$ induced four-cycles in $$$G$$$. They may share vertices.
Second run
In the second run, you play Qianwai. The judge has your complete output from the first run. For each of $$$q$$$ queries, it selects one of your four-cycles, deletes one of its vertices, and gives you the other three vertex numbers. Report the index of the four-cycle in Zhulin's output from which they came.
First run
The first line contains the string send.
The second line contains an integer $$$n$$$ ($$$n=200\,000$$$), the number of induced four-cycles you must output.
The third line contains two integers $$$|V|$$$ and $$$|E|$$$.
Each of the next $$$|E|$$$ lines contains two integers $$$u,v$$$, indicating an undirected edge between vertices $$$u$$$ and $$$v$$$ ($$$1 \le u,v \le |V|$$$).
Second run
The first line contains the string receive.
The second line contains two integers $$$|V|$$$ and $$$|E|$$$.
Each of the next $$$|E|$$$ lines contains two integers $$$u,v$$$, indicating an undirected edge between vertices $$$u$$$ and $$$v$$$ ($$$1 \le u,v \le |V|$$$).
Line $$$|E|+3$$$ contains an integer $$$q$$$ ($$$q=4n$$$), the number of received vertex sets.
Each of the next $$$q$$$ lines contains $$$3$$$ integers: the vertices remaining after the judge removes one vertex from a four-cycle in your first-run output.
First run
Output $$$n$$$ lines. Line $$$i$$$ contains four integers $$$v_1,v_2,v_3,v_4$$$, the vertices of the $$$i$$$-th induced four-cycle.
Second run
Output $$$q$$$ lines. For each received vertex set, output an integer $$$i$$$ ($$$1 \le i \le n$$$), the index of its four-cycle.
send 200000 2000 43600 29 1973 228 1127 ... 92 573
1 174 613 1323 1 955 1683 1755 ... 1390 1615 1683 1777
receive 2000 43600 29 1973 228 1127 ... 92 573 800000 46 1297 1949 1056 1275 1454 ... 387 1289 1533
17713 191947 ... 118231
Parts of the sample are omitted because the complete data is too large.
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