Given a positive integer N, determine how many of the integers between 1 and N are co-prime with N.
Two numbers are co-prime if the only common positive factor of the two numbers is 1.
The input will contain one integer N (0 < N < 1000).
Print a single integer--the number of integers between 1 and N that are co-prime with N.
| Input | Output |
|---|---|
15 | 8 |
| Input | Output |
|---|---|
20 | 8 |