2) var a:integer;
begin
readln (a);
if (a mod 2=0) then writeln(sqr(a)) else writeln (a);
end.
3) var a,b,c:integer;
begin
readln (a,b,c);
if (a>0) then writeln (sqr(a)) else writeln (a);
if (b>0) then writeln (sqr(b)) else writeln (b);
if (c>0) then writeln (sqr(c)) else writeln (c);
end.