1)

var

i:integer;

begin

for i:=-5 to 5 do

writeln (i)

end.

2)

var

i,n:integer;

begin

readln(n);

for i:=1 to n do

writeln (sqr(i))

end.

3)

var

i,sum:integer;

begin

for i:=10 to 20 do

sum:=sum+i;

writeln(sum);

end.