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