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.HashSet;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Main {
    public static long reverseInt(long n){
        long sum = 0;

        while (n != 0) {
            sum = sum + n % 10;
            n = n / 10;
        }
        return sum;
    }
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n = in.nextLong();
        long ans = Integer.MAX_VALUE;
        while(ans>9) {
            ans=reverseInt(n);
            n = ans;
        }
        System.out.println(ans);
    }
}