def f(dp,s)
	dp2=61.times.map{0.0}
	dp.size.times{|i|
		if dp[i]>0
			s.each{|e|
				dp2[i+e]+=dp[i]
			}
		end
	}
	return dp2
end

dp1=61.times.map{0.0}
dp2=61.times.map{0.0}
dp1[0]=1.0
dp2[0]=1.0

n=gets.to_i
m=gets.to_i
n.times{
	dp1=f(dp1,[1,2,3,4,5,6])
}
m.times{
	dp2=f(dp2,[4,5,6,4,5,6])
}
(n-m).times{
	dp2=f(dp2,[1,2,3,4,5,6])
}
sum1=dp1.inject(0){|sum,e|
	sum+e
}
sum2=dp2.inject(0){|sum,e|
	sum+e
}
ans=0.0
dp1.each{|e|
	r1=e/sum1
	dp2.shift
	sum3=dp2.inject(0){|sum,e|
		sum+e
	}
	r2=sum3/sum2
	ans+=r1*r2
}
puts ans