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