Problem Description

Little Frane is in the tenth grade, but he still struggles with learning Pascal in his computer science class. The teacher has written the following Pascal program as homework, and he needs to determine the output of the program based on the input integer \( N \).

readln(N);
counter := 0;
for i := N-1 downto 1 do begin
    counter := counter + 1;
    if N mod i = 0 then break;
end;
writeln(counter); 

Please write a program to solve this problem.

Input Format

A single line containing an integer \( N \).

Output Format

A single line representing the output of the above program.

Sample Input and Output

Sample Input #1

1

Sample Output #1

0

Sample Input #2

10

Sample Output #2

5

Sample Input #3

27

Sample Output #3

18

Notes

For \( 100\% \) of the test cases, \( 1 \le N \le 10^9 \).

This problem is scored according to the original competition settings, with a maximum of \( 30 \) points.

见题面 Input 部分

见题面 Output 部分