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:
def f(n):
    if(n < 10):
        return n
    else:
        return (n%10) + f(int(n/10)) 
x = int(input())
while(x >= 10):
    x =  f(x)
print(x)