Problem I. Digitalization ≡

Statement

Define the function rm sum_of_digits(a) 〈 a ∈ N₀〉   = k∑i = 0a_i where {a_i} is the representation of a in the numeral system with radix 10.

Define the function:

rm digitalization(a) 〈 a ∈ N₀〉   = {
  bf if  rm sum_of_digits(a) ∈ 0..9  {
   bf return  rm sum_of_digits(a)
  }
  bf else  {
   bf return  rm digitalization(rm sum_of_digits(a))
  }
}

Your problem is to find rm digitalization(n!) for given n.

Input file format

n

Output file format

rm digitalization(n!)

Constraints

Sample tests

2

2

3

6