P,C=map(int,raw_input().split())
V=[1]
for i in range(P):
    nextV=[]
    for p in (2,3,5,7,11,13):
        for v in V:
            nextV.append(v*p)
    V=nextV
W=[1]
for c in range(C):
    nextW=[]
    for p in (4,6,8,9,10,12):
        for v in W:
            nextW.append(v*p)
    W=nextW
s=0
for v in V:
    for w in W:
        s+=v*w
print "%.9f"%(s/pow(6.0,C+P))