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 Python (3.4.3) (judge verdict: Runtime Error)

# coding: utf-8
def gcd(x,y):
    if(y==0):
        return x
    return gcd(y,x%y)

def factorize(n):
    i=2
    count = 1 
    while(i*i<=n):
        if(n%i): 
            ++i
            continue
        else:
            ++count
            while(n%i):
                n/=i
            ++i
    return count 
a,b = map(int,input().split())
A = factorize(gcd(a,b))

print(A)