Long long ago，there was a very big forest, called Happy Forest. In the forest, there was a very naughty cat, named Jim. One day, when Jim played in the forest, he was attracted by a beautiful butterfly and followed the butterfly, he went into the dire area, the Black Forest
An evil wizard lived in the Black Forest, he would kill anyone who entered the forest, and had a good meal with their bodies. Obviously, Jim knew what would happen to him. As a clever cat, Jim came up an idea quickly, that is, calling for help.
Unfortunately, the wizard trapped Jim with a magic called Maze, and then he went home prepered for the delicious cat-meet-dinner. He would come back at time T.
The magic Maze transmits somebody to a special square. At there, one must solve a riddle to get out, or waiting for powerful wizard to dispel the Maze.
On the square, there are N rows stone. Each row has M stones. Each stone has its own number, and there are M pieces of stone whose number is k(1<=k<=N). Only all the stone in kth row has the same number k, the person can exit the Maze.
Certainly, Jim didn't want to become a cat-meet-dinner, so he asked you for help.
You can assume Jim would take 1 time from one row to any row (nomatter he took a stone or not), and when start (time 0), he could go to any row he likes.
Notice: even Jim can get out of magic Maze, he also need at least 1 time to call for help.(After that he would save by SuperCat and Wizard would lost his cat-meet-dinner. Clearly he might be crazy and do something terrible. For exmaple, he might summon some vampire to catch the cat Jim and then destroy the Happy Forest:( After all, he was a dread wizard.)