n = int(input())
m = n//2
if n%2==1:
  print((m+1)/n)
else:
  print(m/n) n = int(input()) n int(input()) int input() input m = n//2 m n//2 n 2 if n%2==1:
  print((m+1)/n)
else:
  print(m/n) n%2==1 n%2 n 2 1 print((m+1)/n) print (m+1)/n m+1 m 1 n print(m/n) print m/n m n n = int(input()) int(input()) n m = n//2 n//2 m
n = int(input())
m = n//2
if n%2==1:
  print((m+1)/n)
else:
  print(m/n)