Practice on Toph

Participate in exhilarating programming contests, solve unique algorithm and data structure challenges and be a part of an awesome community.

Making Friends

Limits: 1s, 512 MB

Byang is going to join a new school. His new class has N students.

Each of the students are identified by their roll numbers starting from 1 to N. Byang is going to get the next roll number in the sequence.

Byang plans to make friends with only those whose roll numbers are a divisor of his roll number.

Can you help Byang count how many friends he will make?

Input

The input will contain an integer N (N < 1000000).

Output

Print the number of friends Byang will make in his new class.

Samples

InputOutput
6
3

Discussion