n=float(input())
if int(n)%2==0:
    print(1/2)
else:
    print(float(((n+1)/(2*n)))) n=float(input()) n float(input()) float input() input if int(n)%2==0:
    print(1/2)
else:
    print(float(((n+1)/(2*n)))) int(n)%2==0 int(n)%2 int(n) int n 2 0 print(1/2) print 1/2 1 2 print(float(((n+1)/(2*n)))) print float(((n+1)/(2*n))) float (n+1)/(2*n) n+1 n 1 2*n 2 n n=float(input()) float(input()) n
n=float(input())
if int(n)%2==0:
    print(1/2)
else:
    print(float(((n+1)/(2*n))))