Problem: 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 ≤ a ≤ 1000000).

Output

Output the result – an integer number.

Examples

Input


1


Output


1


Input


81


Output


9

Solution (in JAVA):

Solution:
import java.util.*;

public class ProblemB {
    public static void main(String args[]) {
        Scanner s = new Scanner(System.in);
        int n = Integer.parseInt(s.nextLine());

        int sum = 0;
        while (n > 0 || sum > 9)
        {
            if (n == 0) {
                n = sum;
                sum = 0;
            }
            sum += n % 10;
            n /= 10;
        }
        System.out.println(sum);
    }
}