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