When using the generator with the script format :

generator-name [params] > test-index

eg : gen_rnd 1 100 0 1000 > 1

The test case files get generated.

But when using script format to generate multiple files :

generator-name [params] > {test-indices}

eg : gen_rnd 1 100 0 1000 > {1-2}

The test case file show an error :

Problem :

Sereja wants to answer q queries. In each query, she is given a number N. She wants to find the number of ordered pairs (x, y) such that x and y are factors of N and x and y are coprime.

Constrainsts :

1 ≤ q ≤ 200000

1 ≤ N ≤ 500000

The contest does have an editorial available, but i am unable to understand how the described equation was obtained.