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:
import math
x = int(input())
# print(math.floor(x ** (1/2)))

ans = 0
while True:
    while x > 0:
        ans += x % 10
        x //= 10
    if ans > 9:
        ans, x = 0, ans
    else:
        break
print(ans)