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:
//https://codeforces.com/contest/1505/problem/B
//B. DMCA
import java.util.*;
import java.io.*;
public class CF_1505_B{
	public static void main(String[] args) throws Exception{
		
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
		
		int a = Integer.parseInt(br.readLine());
		int ans = 0;
		
		if(a==0)
			ans = 0;
		else if(a%9==0)
			ans = 9;
		else 
			ans = a%9;

		pw.print(ans);
		pw.flush();
		pw.close();
	}
}