B. Easy Number Challengetime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputLet's denote d(n) as the number of divisors of a positive integer n. You are given three integers a, b and c. Your task is to calculate the following sum:Find the sum modulo 1073741824 (230).InputThe first line contains three space-separated integers a, b and c (1 ≤ a, b, c ≤ 100).OutputPrint a single integer — the required sum modulo 1073741824 (230).ExamplesInput2 2 2Output20Input5 6 7Output1520NoteFor the first example.  d(1·1·1) = d(1) = 1;  d(1·1·2) = d(2) = 2;  d(1·2·1) = d(2) = 2;  d(1·2·2) = d(4) = 3;  d(2·1·1) = d(2) = 2;  d(2·1·2) = d(4) = 3;  d(2·2·1) = d(4) = 3;  d(2·2·2) = d(8) = 4. So the result is 1 + 2 + 2 + 3 + 2 + 3 + 3 + 4 = 20.
Input2 2 2
Output20
['implementation', 'number theory', '*1300']