Write a program to find the repeated sum of digits of a number until it becomes a single-digit number.

Input Format:

The input contains an integer which denotes 'n'

Output Format:

Print the single digit number

Sample Input

88

Sample Output

7

Explanation:

Step 1: 8+8 = 16

Step 2: 1+6 = 7

sum of digits of a number until it becomes a single-digit number which is 7 here.

Solution:

#include<iostream>

using namespace std;

int singleDigit(int n){

  int r = 0, s = 0;

  while(n > 9){

    while(n > 0){

        r = n % 10;

        n = n / 10;

        s += r;

         }  

    n = s;

    s = 0;

  }

  return n;

}

int main(){

  int n;

  cin>>n;

  cout<<singleDigit(n);

}