uses crt;
var a,b,c:word;
function s(a,b,c:word):real;
var p:real;
begin
p:=(a+b+c)/2;
s:=sqrt(p*(p-a)*(p-b)*(p-c));
end;
begin
clrscr;
readln(a,b,c);
if (a+b>c) and (a+c>b) and (b+c>a) then
begin
writeln(a,' ',b,' ',c,'la 3 canh cua tam giac');
writeln(s(a,b,c));
end
else writeln(a,' ',b,' ',c,'khong phai la 3 canh cua tam giac');
readln;
end.