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.*;
import java.io.*;
public class Main
{
  static int digitSum(int n)
  {
    int sum = 0;
    while(n > 0)
    {
      sum += (n % 10);
      n /= 10;
    }
    
    return sum;
  }
  
  public static void main(String[] args) throws IOException
  {
    Scanner read = new Scanner(System.in);
    
    int n = read.nextInt();
    while(n > 9)
    {
      n = digitSum(n);
    }
    
    System.out.println(n);
  }
}