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.io.*;

public class B_DMCA {
    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

    public static void main(String[] args) throws IOException {
        int a = Integer.parseInt(br.readLine());
        while (a >= 10) a = digitSum(a);
        System.out.println(a);
    }

    private static int digitSum(int n) {
        int s = 0;
        while (n > 0) {
            s += n % 10;
            n /= 10;
        }
        return s;
    }
}