Given a natural number n ≥ 1, being s(n) the sum of its divisors not counting itself. A number n ≥ 3 is called popiropis if n = s(n−2) + s(n) + s(n+2). A number n ≥ 3 is called k-popiropis if n*k = s(n−2) + s(n) + s(n+2) for an integer k ≥ 2.
For instance, the number 133 is popiropis, because s(131) = 1, s(133) = 27 and s(135) = 105. Besides, 132 is 3-popiropis, because s(130) + s(132) + s(134) = 396 = 132*3.
Your task is to write a program that, for each natural number given, print if it is popiropis, if is k-popiropis (and which is the value of k), or if it is nothing.
Input
The input is a sequence of natural numbers n ≥ 3.
Output
Your program must print a line for each n, indicating which class is: popiropis, k-popiropis, or nothing.
Observation
Your program must implement and use the function
that, given a natural number |n| different than 0, returns the sum of its divisors (not counting itself).
Input
131 132 133 134
Output
131: nothing 132: 3-popiropis 133: popiropis 134: nothing
Input
3 80 273 38222 44642 1000000 1629073 8802908
Output
3: nothing 80: 3-popiropis 273: popiropis 38222: 4-popiropis 44642: 4-popiropis 1000000: nothing 1629073: popiropis 8802908: 3-popiropis