def equalStacks(h1, h2, h3):
    s1 = set(accumulate(reversed(h1), lambda s, n: s + n))
    s2 = set(accumulate(reversed(h2), lambda s, n: s + n))
    s3 = set(accumulate(reversed(h3), lambda s, n: s + n))
    
    return max(s1 & s2 & s3, default=0)