saikoro = [0]*(13*12+1)
for i in [2,3,5,7,11,13]:
    for j in [4,6,8,9,10,12]:
        saikoro[i*j] += 1
P, C = map(int, input().split())
ans = 0
for cnt, i in enumerate(saikoro):
    ans += cnt * i /36
print(ans)