N = int(input())
if N/2 == N//2:
        print(0.5)
else:
        print((N//2 + 1)/N) N = int(input()) N int(input()) int input() input if N/2 == N//2:
        print(0.5)
else:
        print((N//2 + 1)/N) N/2 == N//2 N/2 N 2 N//2 N 2 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/2 == N//2:
        print(0.5)
else:
        print((N//2 + 1)/N)