#include <iostream>
using namespace std;
int root(int a)
{
    int s = 0;
    while(a > 0)
    {
        s += a % 10;
        a /= 10;
    }
    if(s > 9) return root(s);
    else return s;
}
int main()
{
    int a;
     cin >> a;
    cout << root(a) << endl;
   return 0;
}
### Prompt

In Cpp, your task is to solve 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>
using namespace std;
int root(int a)
{
    int s = 0;
    while(a > 0)
    {
        s += a % 10;
        a /= 10;
    }
    if(s > 9) return root(s);
    else return s;
}
int main()
{
    int a;
     cin >> a;
    cout << root(a) << endl;
   return 0;
}
```