n=int(input())
if n%2==0:
    print(n/2/n)
else:
    print((n-(n//2))/n) n=int(input()) n int(input()) int input() input if n%2==0:
    print(n/2/n)
else:
    print((n-(n//2))/n) n%2==0 n%2 n 2 0 print(n/2/n) print n/2/n n/2 n 2 n print((n-(n//2))/n) print (n-(n//2))/n n-(n//2) n n//2 n 2 n n=int(input()) int(input()) n
n=int(input())
if n%2==0:
    print(n/2/n)
else:
    print((n-(n//2))/n)
