B. DMCAtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputMany people are aware of DMCA – Digital Millennium Copyright Act. But another recently proposed DMCA – Digital Millennium Calculation Act – is much less known.In this problem you need to find a root of a number according to this new DMCA law.InputThe input contains a single integer a (1 \le a \le 1000000).OutputOutput the result – an integer number.ExamplesInput
1
Output
1
Input
81
Output
9

1

1 
['*special problem', 'implementation', 'number theory', '*1600']