#include <bits/stdc++.h>
#define N 200005
using namespace std;

void solve(){
    int a;
    cin >> a;
    int sum = 0;
    while(a >= 10){
        sum = 0;
        while(a){
            sum += a%10;
            a /= 10;
        }
        a = sum;
    }
    cout << a;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    #ifdef Local
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
    #endif
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    #ifdef Local
    cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}
### Prompt

Construct a cpp code solution to the problem outlined:

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>
#define N 200005
using namespace std;

void solve(){
    int a;
    cin >> a;
    int sum = 0;
    while(a >= 10){
        sum = 0;
        while(a){
            sum += a%10;
            a /= 10;
        }
        a = sum;
    }
    cout << a;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    #ifdef Local
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
    #endif
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    #ifdef Local
    cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}
```