var x,y:real;
begin
write('Vvedite sna4ala x i 4erez probel y');
readln(x,y);
if (y>=-x-4) and (y>=x-4) and (y<=0) then writeln('yes') else writeln('no');
readln
end.
var x,y:real;
begin
write('Vvedite sna4ala x i 4erez probel y');
readln(x,y);
if (y>=-x-4) and (y>=x-4) and (y<=0) then writeln('yes') else writeln('no');
readln
end.