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

Solution (in CPP):

Solution:
#include <bits/stdc++.h>

#define int long long

using namespace std;

signed main(){
    int a;
    cin >> a;
    int x = 0;
    while(a){
        x = (x+a%10)%9;
        a/=10;
    }
    if(x==0) x += 9;
    cout << x << "\n";
}