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 PYTHON3):

Solution:
"""
CONTESTANT: ngtien2
CONTEST: April Fools Day Contest 2021
LANGUAGE: Python 3.7
PROBLEM: B. DMCA
"""


def digit_root(n):
    s = str(n)
    m = sum((int(char) for char in s))
    if m < 10:
        return m
    else:
        return digit_root(m)


n = int(input())
print(digit_root(n))