P1055 [NOIP 2008 Junior] ISBN Number

Every formally published book has an ISBN number associated with it. An ISBN consists of $9$ digits, $1$ check digit, and $3$ separators. Its prescribed format is `x-xxx-xxxxx-x`, where the symbol `-` is the separator (the minus sign on the keyboard), and the last character is the check digit. For example, `0-670-82162-4` is a standard ISBN. The first digit indicates the publication language of the book (for example, $0$ represents English); the three digits after the first separator `-` indicate the publisher (for example, $670$ represents Viking Press); the five digits after the second separator indicate the book’s identifier at that publisher; the last character is the check digit. The check digit is computed as follows: Multiply the first digit by $1$, add the second digit multiplied by $2$, and so on. Take the resulting sum $\bmod 11$; the remainder is the check digit. If the remainder is $10$, then the check digit is the uppercase letter $X$. For example, in the ISBN `0-670-82162-4`, the check digit $4$ is obtained as follows: take the nine digits `067082162` from left to right, multiply them by $1,2,\dots,9$ respectively and sum, i.e., $0\times 1 + 6\times 2 + \cdots + 2\times 9 = 158$, then take $158 \bmod 11$, whose result $4$ is the check digit. Your task is to write a program to determine whether the check digit in the input ISBN number is correct. If it is correct, output `Right` only; if it is incorrect, output the ISBN number you believe to be correct.

A character sequence representing a book’s ISBN number (the input is guaranteed to conform to the format requirements of ISBN numbers).

One line. If the check digit of the input ISBN number is correct, output `Right`; otherwise, output the correct ISBN number in the prescribed format (including the separator `-`).

2008 Junior Problem 1. Translated by ChatGPT 5