uses crt;
var a,b,c:real;
begin
clrscr;
writeln(' nhap ba so a b c ');
readln(a,b,c);
if (a<=0) or (b<=0) or (c<=0) or ((a+b)<c) or ((b+c)<a) or ((a+c)<b) then writeln(' khong ton tai tam giac co 3 canh a b c') else
if a=b=c then writeln(' tam giac co 3 canh a b c la tam giac deu ') else writeln('tam giac co 3 canh a b c khong la tam giac deu');
readln
end.