Many 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.

Input

The input contains a single integer $a$ ($1 \le a \le 1000000$).

Output

Output the result – an integer number.

见题面 Input 部分

见题面 Output 部分