Competitions

# Unexpressed

One integer n is given. How many integers between 1 and n (inclusive) are unrepresentable as ab, where a and b are integers not less than 2?

#### Input

One positive integer n (n1010).

#### Output

Print the amount of unrepresentable numbers.

Time limit 1 second
Memory limit 128 MiB
Input example #1
8

Output example #1
6

Input example #2
100000

Output example #2
99634