import math
import itertools
n = int(input())
 
if(n %2 == 1):
    d = int((n-1)/2) + 1
else:
    d = int(n/2)
 
ans = d/n
 
print('{:.08f}'.format(ans)) import math math import itertools itertools n = int(input()) n int(input()) int input() input if(n %2 == 1):
    d = int((n-1)/2) + 1
else:
    d = int(n/2)
  n %2 == 1 n %2 n 2 1 d = int((n-1)/2) + 1 d int((n-1)/2) + 1 int((n-1)/2) int (n-1)/2 n-1 n 1 2 1 d = int(n/2) d int(n/2) int n/2 n 2 ans = d/n ans d/n d n print('{:.08f}'.format(ans)) print '{:.08f}'.format(ans) '{:.08f}'.format '{:.08f}' format ans d = int(n/2) int(n/2) d n = int(input()) int(input()) n d = int((n-1)/2) + 1 int((n-1)/2) + 1 d ans = d/n d/n ans
import math
import itertools
n = int(input())
 
if(n %2 == 1):
    d = int((n-1)/2) + 1
else:
    d = int(n/2)
 
ans = d/n
 
print('{:.08f}'.format(ans))