This is how I started coding......... in SAS

data marriedlife;
input motherinlaw sisterinlaw;
datalines;
1220000 560000
;
run;
***** deriving husband *******;
data husband_temp;
set marriedlife;
if motherinlaw ne . and sisterinlaw ne . then do;
husband = motherinlaw + sisterinlaw;
end;
drop motherinlaw sisterinlaw;
run;

data laterinlife;
input salary pension;
datalines;
1570000 650000
;
run;
***** deriving life *******;
data mylife_permanent;
set laterinlife;
if salary ne . and pension ne . then do;
husband = salary + pension;
mylife=husband;
end;
drop husband;
run;

Just for fun ;)