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.Scanner;

/**
 *
 * @author Acer
 */
public class Main {
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Main sd = new Main();
        int x = sd.sumOfDigit(n);
        while(x >= 10){
            x = sd.sumOfDigit(x);
        }
        System.out.println(x);     
    }
    
    public int sumOfDigit(int a){
        int sum = 0;
        while(a != 0){
            sum += a%10;
            a = a/10;
        }
        return sum;      
    }
    
}