n=int(input())
a=0
for i in range(1,n+1):
  a+=(i%2)
print(a/n) n=int(input()) n int(input()) int input() input a=0 a 0 for i in range(1,n+1):
  a+=(i%2) i range(1,n+1) range 1 n+1 n 1 a+=(i%2) a i%2 i 2 print(a/n) print a/n a n a=0 0 a a+=(i%2) i%2 a n=int(input()) int(input()) n
n=int(input())
a=0
for i in range(1,n+1):
  a+=(i%2)
print(a/n)