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:
x = int(input())
if(x%9==0): print(9)
else:
    while(True):
        y=0
        while(x>0):
            if((x%10)==9):
                x=x//10
            else:
                y+=(x%10)
                x=x//10
        if(y>=1 and y<=9):
            break
        x=y
    print(y)