cCache = dict(((0,)*i, 1) for i in range(20))
def c(a):
    try:
        return cCache[a]
    except KeyError:
        res = sum(d(i, a) for i in range(len(a)))
        cCache[a] = res
        return res
 
dCache = dict()
def d(i, a):
    try:
        return dCache[(i, a)]
    except KeyError:
        if a[i] == 0:
            return 0
        aa = list(a)
        aa[i] -= 1
        aa = tuple(aa)
        res = c(aa) - d(i, aa)
        dCache[(i, a)] = res
        return res
 
print(c((3, 2, 2)))
 

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