Hello,
I try to generate a variable that is includes missing, how can I ignore these missing values

A002112000 A002113000 A002114000 A002115000 A0i2116000 A0i2117000
7.851e+09 2.904e+10
862729.14 -1401101.7 0 212157.58 0 0
1142823 2853657.8 0 8015518.9 0 0
2490640.9 7834515.8 0 3013278 0 0
2170997.8 3045616 0 2813278 0 0
2003422.3 1464629.9 2813278
1995585.5 4733366.3 2813278


I need to generate HH=A002112000 + A002113000 - A002114000 - A002115000 - A0i2116000 - A0i2117000