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