n= int(raw_input())
print float((n/2) + 1)/n if n % 2 else 0.5 n= int(raw_input()) n int(raw_input()) int raw_input() raw_input print float((n/2) + 1)/n if n % 2 else 0.5 n % 2 n 2 float((n/2) + 1)/n float((n/2) + 1) float (n/2) + 1 n/2 n 2 1 n 0.5 n= int(raw_input()) int(raw_input()) n
n= int(raw_input())
print float((n/2) + 1)/n if n % 2 else 0.5
