Помогите составить программу. - вопрос №1059434

uses crt;
var a,st:real; p,q,n:integer;
begin
write('vvedite stoimosty v mae a='); readln(a);
write('vvedite procent v iune p='); readln(p);
write('vvedite procent v avguste q='); readln(q);
writeln('vvedite nomer mesyaca 5-8');
readln(n);
case n of
5:writeln('st=',a:8:2);
6:writeln('st=',a+a*p/100:8:2);
7:writeln('st=',a:8:2);
8:writeln('st=',a-a*q/100:8:2)
else writeln('vvedite pravilniy mesyac');
end;
readln
end.

или вариант с if 

uses crt;
var a,st:real; p,q,n:integer;
begin
write('vvedite stoimosty v mae a='); readln(a);
write('vvedite procent v iune p='); readln(p);
write('vvedite procent v avguste q='); readln(q);
writeln('vvedite nomer mesyaca 5-8');
readln(n);
if n=5 then writeln('st=',a:8:2)
else if n=6 then writeln('st=',a+a*p/100:8:2)
else if n=7 then writeln('st=',a:8:2)
else if n=8 then writeln('st=',a-a*q/100:8:2)
else writeln('vvedite pravilniy mesyac');
readln
end.