CCC '01 J2 - Mod Inverse


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Points: 1
Time limit: 2.0s
Memory limit: 256M

Problem type
Allowed languages
C++, Python
Canadian Computing Competition: 2001 Stage 1, Junior #2

In many cryptographic applications, the Modular Inverse is a key point. This question involves finding the modular inverse of a number.

Given \(0 < x < m\) , where \(x\) and \(m\) are integers, the modular inverse of \(x\) is the unique integer \(n\) , \(0 < n < m\) , such that the remainder upon dividing \(x \times n\) by \(m\) is \(1\) .

For example, \(4 \times 13 = 52 = 17 \times 3 + 1\) , so the remainder when \(52\) is divided by \(17\) is \(1\) , and thus \(13\) is the inverse of \(4\) modulo \(17\) .

You are to write a program which accepts as input the two integers \(x\) and \(m\) , and outputs either the modular inverse \(n\) , or the statement No such integer exists. if there is no such integer \(n\) .

Constraints

\(m \le 100\)

Sample Input 1

4
17

Sample Output 1

13

Sample Input 2

6
10

Sample Output 2

No such integer exists.

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