#P4780. Minimum Number Satisfying Euler's Totient Equation
Minimum Number Satisfying Euler's Totient Equation
Minimum Number Satisfying Euler's Totient Equation
Given a positive integer n, find the smallest positive integer x such that the Euler's totient function \(\varphi(x) = n\). If no such positive integer exists, output -1.
The Euler's totient function \(\varphi(x)\) is defined as the number of integers in \([1, x]\) that are coprime with x.
inputFormat
The input consists of a single line that contains a positive integer n.
outputFormat
Output the smallest positive integer x for which \(\varphi(x) = n\). If no such x exists, output -1.
sample
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1