|A+B| = | a+b,2c1,2c2,2c3 |
= | a,2c1,2c2,2c3 | + | b,2c1,2c2,2c3 |
= 8 | a,c1,c2,c3 | + 8| b,c1,c2,c3 |
= 8*2 + 8*3
= 40.