import math
import sys
N=int(input())
sum=0
if N==1:
    print(1)
    sys.exit()
for i in range(1,N+1):
    if i%2==1:
        sum+=1
print(sum/N) import math math import sys sys N=int(input()) N int(input()) int input() input sum=0 sum 0 if N==1:
    print(1)
    sys.exit() N==1 N 1 print(1) print 1 sys.exit() sys.exit sys exit for i in range(1,N+1):
    if i%2==1:
        sum+=1 i range(1,N+1) range 1 N+1 N 1 if i%2==1:
        sum+=1 i%2==1 i%2 i 2 1 sum+=1 sum 1 print(sum/N) print sum/N sum N sum=0 0 sum N=int(input()) int(input()) N sum+=1 1 sum
import math
import sys
N=int(input())
sum=0
if N==1:
    print(1)
    sys.exit()
for i in range(1,N+1):
    if i%2==1:
        sum+=1
print(sum/N)