N = int(input())

print(1/2 if N%2==0 else (N+1)/(2*N)) N = int(input()) N int(input()) int input() input print(1/2 if N%2==0 else (N+1)/(2*N)) print 1/2 if N%2==0 else (N+1)/(2*N) N%2==0 N%2 N 2 0 1/2 1 2 (N+1)/(2*N) N+1 N 1 2*N 2 N N = int(input()) int(input()) N
N = int(input())

print(1/2 if N%2==0 else (N+1)/(2*N))