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:
from sys import stdin, gettrace

if gettrace():
    def inputi():
        return input()
else:
    def input():
        return next(stdin)[:-1]


    def inputi():
        return stdin.buffer.readline()


def main():
    a = int(input())
    while a >= 10:
        b = a
        a = 0
        while b > 0:
            a += b%10
            b //= 10
    print(a)


if __name__ == "__main__":
    main()