# visible 
# Fig. 6.6 
# input: 10 or 20 or 40

from gcdrec import gcd

n = int(input("n=? "))
s = 0
for i in range(1, n+1):
  for j in range(1, n+1):
    if gcd(i,j) == 1:
      s += 1
p = s/n/n
print(f"s == {s} p == {p:.8f}")