input = raw_input().split(' ')
P = int(input[0])
C = int(input[1])
sosu = [[2.0,1.0/6],[3.0,1.0/6],[5.0,1.0/6],[7.0,1.0/6],[11.0,1.0/6],[13.0,1.0/6]]
gouseisu = [[4.0,1.0/6],[6.0,1.0/6],[8.0,1.0/6],[9.0,1.0/6],[10.0,1.0/6],[12.0,1.0/6]]

def cal(list,saikoro,n):
	if n == 0:
		return list
	else:
		if len(list) == 0:
			list = saikoro
		copy = saikoro	

	if n == 1:
		return saikoro
	else:
		for vp in list:
			for cp in copy:
			    list.append([cp[0]*vp[0],cp[1]*vp[1]])
    	return cal(list,saikoro,int(n)-1)

s_list = []
g_list = []
s_out = cal(s_list,sosu,P)
g_out = cal(g_list,gouseisu,C)
sss = 0.0
ggg = 0.0
for tmp in s_out:
    sss += tmp[0]*tmp[1]
for tmp in g_out:
    ggg += tmp[0]*tmp[1]

print sss+ggg