怎么才能简化我的这个公式呢?太长了.

怎么才能简化我的这个公式呢?太长了.
=IF(B2="A6HG30","E6",IF(B2="A6HG31","B2",IF(B2="A1HG30","D1",IF(B2="A1HG31","D1",IF(B2="A1MG31","D2",IF(B2="A6SG30","A3",IF(B2="A6SG31","A3",IF(B2="F1CG31","C1",IF(B2="F4CG31","B3",IF(B2="F8CG30","D3",IF(B2="S2HG31","C3",IF(B2="S2HG30","B3",IF(B2="S4HG31","B3",IF(B2="S4HG30","B3",IF(B2="S4HG40","B3",IF(B2="S8HG30","D4",IF(B2="S9HG31","B1",IF(B2="S9HG30","B1",IF(B2="S9HG40","D4",IF(B2="SF1870","B3",IF(B2="W1HG30","D4")))))))))))))))))))))
另个,我这个公式是输入在H2的,要怎么才能让B2没有输入信息或者信息不满足这里面的条件的情况下,让H2显示空白呢?.