20. Digital Root
Calculate the digital root of the given number. The digital root is defined by the following expression:
DigitalRoot(x)={xif x < 10DigitalRoot(SumOfDigits(x))otherwise
Input
On the first line, a natural number n(1≤n≤1030).
Output
The solution to the problem in a single line.
Sample input 1
8
Sample output 1
8
Sample input 2
11
Sample output 2
2
Sample input 3
173
Sample output 3
2
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MediumMathLoops
387 / 33
Solved / unsolved count
1.0 s / 512 MB
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