#P4449. GCD Power Sum
GCD Power Sum
GCD Power Sum
Given three integers \(n\), \(m\), and \(k\), compute the following sum:
\[ S = \sum_{i=1}^{n} \sum_{j=1}^{m} \gcd(i,j)^k \]Output the value of \(S\) modulo \(10^9+7\).
inputFormat
The input consists of a single line containing three space-separated integers \(n\), \(m\), and \(k\).
outputFormat
Output a single integer, which is the sum \(S\) modulo \(10^9+7\).
sample
3 3 1
12
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