print((lambda x:(1/2 if (x%2 == 0) else (x//2+1)/x))(int(input()))) print((lambda x:(1/2 if (x%2 == 0) else (x//2+1)/x))(int(input()))) print (lambda x:(1/2 if (x%2 == 0) else (x//2+1)/x))(int(input())) lambda x:(1/2 if (x%2 == 0) else (x//2+1)/x) 1/2 if (x%2 == 0) else (x//2+1)/x x%2 == 0 x%2 x 2 0 1/2 1 2 (x//2+1)/x x//2+1 x//2 x 2 1 x x int(input()) int input() input
print((lambda x:(1/2 if (x%2 == 0) else (x//2+1)/x))(int(input())))
