uses crt;
var f1,f2:text;
a,b,c:integer;
p,s:real;
begin
assign(f1,'bt1.inp'); reset(f1);
assign(f2,'bt2.out'); rewrite(f2);
read(f1,a,b,c);
if (a+b>c) or (b+c>a) or (a+c>b) then
begin
p:=(a+b+c)/2;
s:=sqrt(p*(p-a)*(p-b)*(p-c));
end
else writeln(f2,'3 canh a,b,c khong la 3 canh cua tam giac');
writeln(f2,'Chu vi la: ',p*2:4:2,',dien tich la: ',s:4:2);
close(f1); close(f2);
end.