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>
using namespace std;

#define LL long long

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