#The challenge

#Rules

#Test cases

The challenge

Rules

Test cases

Consider for example n=25. We initiallize t = 25. Since this is not a prime nor 1, we compute f(25), which is 9. This becomes the new value for t. This is not a prime nor 1, so we continue: f(9) is 4. We continue again: f(4) is 2. Since this is a prime we stop here. We have done 3 iterations (from 25 to 9, then to 4, then to 2). Thus s(25) is 3.

Consider for example n=25. We initiallize t = 25. Since this is not a prime nor 1, we compute f(25), which is 9. This becomes the new value for t. This is not a prime nor 1, so we continue: f(9) is 4. We continue again: f(4) is 2. Since this is a prime we stop here. We have done 3 iterations (from 25 to 9, then to 4, then to 2). Thus s(25) is 3.

• Initiallize t to n.
• As long as t is not a prime, replace t by f(t) and iterate.
• The number of iterations is s(n).

• Initiallize t to n.
• As long as t is neither prime nor 1, replace t by f(t) and iterate.
• The number of iterations is s(n).