n = int(input())
print(0.5) if n%2==0 else print(int(n/2+1)/n) n = int(input()) n int(input()) int input() input print(0.5) if n%2==0 else print(int(n/2+1)/n) n%2==0 n%2 n 2 0 print(0.5) print 0.5 print(int(n/2+1)/n) print int(n/2+1)/n int(n/2+1) int n/2+1 n/2 n 2 1 n n = int(input()) int(input()) n
n = int(input())
print(0.5) if n%2==0 else print(int(n/2+1)/n)