n=int(input())
if n==1:
	print('1')
elif n%2==0:
	print('0.5')
else:
	print(((n//2)+1)/n) n=int(input()) n int(input()) int input() input if n==1:
	print('1')
elif n%2==0:
	print('0.5')
else:
	print(((n//2)+1)/n) n==1 n 1 print('1') print '1' elif n%2==0:
	print('0.5') n%2==0 n%2 n 2 0 print('0.5') print '0.5' print(((n//2)+1)/n) print ((n//2)+1)/n (n//2)+1 n//2 n 2 1 n n=int(input()) int(input()) n
n=int(input())
if n==1:
	print('1')
elif n%2==0:
	print('0.5')
else:
	print(((n//2)+1)/n)