from collections import Counter
K = int(input())
P = [2, 3, 5, 7, 11, 13]
C = [4, 6, 8, 9, 10, 12]
PDC = []
for i in P:
    for j in C:
        PDC += [i*j]
if(K in PDC):
    print(Counter(PDC)[K]/len(PDC))
else:
    print(0)