#include <iostream>
#include <math.h>
using namespace std;
int a;
int main()
{
    cin >> a;
    int prev = a;
    while (true) {
        int tmp = 0;
        while (prev) {
            tmp += prev % 10;
            prev /= 10;
        }
        if (tmp < 10) {
            cout << tmp << endl;
            break;
        } else {
            prev = tmp;
        }
    }
}

### Prompt

Please create a solution in CPP to the following 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

### Response

```cpp
#include <iostream>
#include <math.h>
using namespace std;
int a;
int main()
{
    cin >> a;
    int prev = a;
    while (true) {
        int tmp = 0;
        while (prev) {
            tmp += prev % 10;
            prev /= 10;
        }
        if (tmp < 10) {
            cout << tmp << endl;
            break;
        } else {
            prev = tmp;
        }
    }
}

```