#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

ll sumofdigits(ll n)
{
    ll sum = 0;
    while (n > 0 || sum > 9)
    {
        if (n == 0)
        {
            n = sum;
            sum = 0;
        }
        sum += n % 10;
        n /= 10;
    }
    return sum;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    ll n;
    cin >> n;
    cout << sumofdigits(n) << endl;
    return 0;
}
### Prompt

Please formulate a CPP solution 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 <bits/stdc++.h>
using namespace std;
typedef long long int ll;

ll sumofdigits(ll n)
{
    ll sum = 0;
    while (n > 0 || sum > 9)
    {
        if (n == 0)
        {
            n = sum;
            sum = 0;
        }
        sum += n % 10;
        n /= 10;
    }
    return sum;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    ll n;
    cin >> n;
    cout << sumofdigits(n) << endl;
    return 0;
}
```