N=int(input())

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

p=0
for i in range(N+1):
    if i%2==1:
        p +=1
print(p/N)