给出一个正整数n，可以多次操作，每次操作可以把n减去一个和n互质的数。问n的最小可能值（最小为1）。 继续阅读【思维】Definite Game
Codehorses has just hosted the second Codehorses Cup. This year, the same as the previous one, organizers are giving T-shirts for the winners.
The valid sizes of T-shirts are either “M” or from to “X” followed by “S” or “L”. For example, sizes “M”, “XXS”, “L”, “XXXL” are valid and “XM”, “Z”, “XXXXL” are not.
There is a beautiful garden of stones in Innopolis.
Its most beautiful place is the nn piles with stones numbered from 11 to nn.
EJOI participants have visited this place twice.
When they first visited it, the number of stones in piles was x1,x2,…,xnx1,x2,…,xn, correspondingly. One of the participants wrote down this sequence in a notebook.
They visited it again the following day, and the number of stones in piles was equal to y1,y2,…,yny1,y2,…,yn. One of the participants also wrote it down in a notebook.
It is well known that every member of the EJOI jury during the night either sits in the room 108108 or comes to the place with stones. Each jury member who comes there either takes one stone for himself or moves one stone from one pile to another. We can assume that there is an unlimited number of jury members. No one except the jury goes to the place with stones at night.
Participants want to know whether their notes can be correct or they are sure to have made a mistake.