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<iostream>
#include<cmath>
using namespace std;

int main(){
int n;
int sum=0;
cin>>n;
while(!(n/10==0 && n%10==0)){sum+=n%10;n/=10;}
if(sum%9==0)cout<<"9\n";
else cout<<sum%9<<"\n";
}