类型错误:不能将序列乘以“float”类型的非整型。Python 3

first = int(list1[0] + list1[1]) 

a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,a16,a17,a18,a19,a20,a21,a22,a23 = map(float, list1)

if first == 11:
            c = con.execute("SELECT Centroid FROM Centroid WHERE ItemID = 1")
            centroid = c.fetchone()
            AA = (min(a1, a2) * centroid) + (pow(a3,2))
            BB = (min(a1, a2) + a3)
            WA = AA/BB
            print (WA)
first = int(list1[0] + list1[1]) 

a1,a2,a3,a4,