字符串相乘

def solve():
    def multiply(____):
        if num1 == '____' or num2 == '____':
            return '____'
        m, n = len(____), len(____)
        result = [____] * (____)
        for i in range(____):
            for j in range(____):
                mul = (ord(____) - ord(____)) * (ord(____) - ord(____))
                p1, p2 = i + j, i + j + ____
                total = mul + result[p2]
                result[p2] = total % ____
                result[p1] += total // ____
        i = ____
        while i < len(____) and result[i] == ____:
            i += ____
        return '____'.join(str(____) for x in result[i:])
    print(multiply(____))