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:
#!/usr/bin/env python

import math
import sys


def main():
    x = sum(int(c) for c in sys.stdin.readline().strip())
    while x >= 10:
        x = sum(int(c) for c in str(x))
    print(x)


if __name__ == "__main__":
    main()