помогите с информатикой плиз

Const a:array[1..8]of integer=(-3, -4, 5, 3, 2, 1, 6, -5);
t:real=0; n=8;
Var x:real; i,b,k:integer;
begin
b:=a[a[3]]+a[a[5]]; inc(b,3);
case b of
1: begin for i:=1 to n do t:=t+sqr(a); t:=sqrt(t) end;

3: begin for i:=1 to n do t:=t+exp(3*ln(a)); t:=sqrt(t) end;

5: begin for k:=n downto 1 do if (k=n) or (t>a[k]) then t:=a[k] end;

7: begin for k:=n downto 1 do if 0>a[k] then t:=a[k] end;
end;
writeln(Trunc(t))
end.