n = int(input())
a = 0
for i in range(n):
    if i%2 == 0:
        a +=1
print(a/n) n = int(input()) n int(input()) int input() input a = 0 a 0 for i in range(n):
    if i%2 == 0:
        a +=1 i range(n) range n if i%2 == 0:
        a +=1 i%2 == 0 i%2 i 2 0 a +=1 a 1 print(a/n) print a/n a n a = 0 0 a a +=1 1 a n = int(input()) int(input()) n
n = int(input())
a = 0
for i in range(n):
    if i%2 == 0:
        a +=1
print(a/n)