Problem:
Score : 100 points

Problem Statement

Given is an integer N.

Takahashi chooses an integer a from the positive integers not greater than N with equal probability.

Find the probability that a is odd.

Constraints

1 \leq N \leq 100

Input

Input is given from Standard Input in the following format:

N

Output

Print the probability that a is odd.
Your output will be considered correct when its absolute or relative error from the judge's output is at most 10^{-6}.

Sample Input 1

4

Sample Output 1

0.5000000000

There are four positive integers not greater than 4: 1, 2, 3, and 4. Among them, we have two odd numbers: 1 and 3. Thus, the answer is \frac{2}{4} = 0.5.

Sample Input 2

5

Sample Output 2

0.6000000000

Sample Input 3

1

Sample Output 3

1.0000000000

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.Scanner;
public class Main{
	public static void main(String[] args){
    	Scanner sc=new Scanner(System.in);
        long a=sc.nextLong();
      	long b=sc.nextLong();
    	long c=gcd(a,b);
      int d=1;
      
      for(int i=2; i*i<=c;i++){
        if(c%i!=0){continue;}
      	while(c%i==0){
        	c=c/i;
        }
        d++;
      }
      if(c>1){d++;}
      System.out.println(d);
        
    }
  	
  	private static long gcd(long a, long b){
    	while(b%a!=0){
        	long c=b%a;
          	b=a;
          	a=c;
        }
      return a;
    }
  
}