#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mx max_element
#define mn min_element
using ld = long double; 
using s = string; 
using ll = long long; 
using pi = pair<int,int>;
using pl = pair<ll,ll>;
using pd = pair<ld,ld>;
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<ld>; 
using vs = vector<s>;
using vpi = vector<pi>;
using vpl = vector<pl>; 
using vpd = vector<pd>;

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    ll n;
    cin >> n;
    ll sum = 0;
    while (n > 9) {
        sum = 0;
        while (n) {
            sum += (n % 10);
            n /= 10;
        }
        n = sum;
    }
    cout << n;
} 
### 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 <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mx max_element
#define mn min_element
using ld = long double; 
using s = string; 
using ll = long long; 
using pi = pair<int,int>;
using pl = pair<ll,ll>;
using pd = pair<ld,ld>;
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<ld>; 
using vs = vector<s>;
using vpi = vector<pi>;
using vpl = vector<pl>; 
using vpd = vector<pd>;

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    ll n;
    cin >> n;
    ll sum = 0;
    while (n > 9) {
        sum = 0;
        while (n) {
            sum += (n % 10);
            n /= 10;
        }
        n = sum;
    }
    cout << n;
} 
```