n = int(input())
c = 0
for i in range(1,n):
      if (i%2==1):
            c+=1
print("{0:.10f}".format(1-(c/n))) n = int(input()) n int(input()) int input() input c = 0 c 0 for i in range(1,n):
      if (i%2==1):
            c+=1 i range(1,n) range 1 n if (i%2==1):
            c+=1 i%2==1 i%2 i 2 1 c+=1 c 1 print("{0:.10f}".format(1-(c/n))) print "{0:.10f}".format(1-(c/n)) "{0:.10f}".format "{0:.10f}" format 1-(c/n) 1 c/n c n c = 0 0 c c+=1 1 c n = int(input()) int(input()) n
n = int(input())
c = 0
for i in range(1,n):
      if (i%2==1):
            c+=1
print("{0:.10f}".format(1-(c/n)))
