// Sum of Digits Using Recursion : Time Complexity : O(d), Space Complexity : O(d) 
// where d is the number of digits in number

import java.io.*;
import java.util.*;

class GFG 
{
	static int fun(int n)
	{
		if(n < 10)
			return n;

		return fun(n / 10) + n % 10;
	}
    public static void main(String [] args) 
    {
    	System.out.println(fun(253));
    }
}


// Iterative : Time Complexity : O(d), Space Complexity : O(1) {No Overhead & Less Aux. Space}

	static int getSum(int n)
	{
		int sum = 0;

		while (n != 0) {
			sum = sum + n % 10;
			n = n / 10;
		}

		return sum;
	}