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 DMCA {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		Scanner in = new Scanner(System.in);
		long n = in.nextLong();

		while (n>=10) n = digitSum(n);
		System.out.println(n);
	}
	
	public static double root(long n) {
		double ans = n; double t;
		do {
			t = ans;
			ans = (ans+(n/ans))/2;
		} while (t-ans!=0.0);
		return ans;
	}
	
	public static long digitSum(long n) {
		long ans=0;
		while (n>0) {
			ans += n%10;
			n/=10;
		}
		return ans;
	}

}