#include<bits/stdc++.h>
using namespace std;

#define int long long
const int T = 64;
int Digitsum(int x){
    int res  = 0;
    while(x){
        int r = x % 10;
        res+= r;
        x/=10;

    }
    return res;
}
int n;
signed main(){
    cin >> n;
    while(n>=10){
        n = Digitsum(n);

    }
    cout << n;
}

### Prompt

Your challenge is to write 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;

#define int long long
const int T = 64;
int Digitsum(int x){
    int res  = 0;
    while(x){
        int r = x % 10;
        res+= r;
        x/=10;

    }
    return res;
}
int n;
signed main(){
    cin >> n;
    while(n>=10){
        n = Digitsum(n);

    }
    cout << n;
}

```