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;
const int N = 1e6 + 5;

int n;

int32_t main() {
	cin.tie(0)->sync_with_stdio(0);
	cin >> n;
	int sum = 0;
	int c = n;
	while (true) {
		int sum = 0;
		string s = to_string(c);
		for (auto &x : s) {
			sum += x - '0';
		}
		if (sum < 10) {
			cout << sum;
			return 0;
		}
		c = sum;
	}
	cout << sum;
}