Câu 1:
uses crt;
var n:word;
function powTwo(n:word):longint;
begin
exit(sqr(n));
end;
begin
clrscr;
readln(n);
write(powTwo(n));
readln;
end.
Câu 2:
uses crt;
var n:longint;
procedure check();
var scan:boolean;
begin
if n<0 then write('n is a negative number')
else if n>0 then write('n is a positive number')
else write('n is equal to 0');
end;
begin
clrscr;
readln(n);
check();
readln;
end.