n = int(input())
cnt = 0
for i in range(1,n+1):
    if i%2==1:
        cnt+=1
print("%.6f"%(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==1:
        cnt+=1 i range(1,n+1) range 1 n+1 n 1 if i%2==1:
        cnt+=1 i%2==1 i%2 i 2 1 cnt+=1 cnt 1 print("%.6f"%(cnt/n)) print "%.6f"%(cnt/n) "%.6f" cnt/n cnt n n = int(input()) int(input()) n cnt = 0 0 cnt cnt+=1 1 cnt
n = int(input())
cnt = 0
for i in range(1,n+1):
    if i%2==1:
        cnt+=1
print("%.6f"%(cnt/n))