uses crt;
const fi='input.inp';
var f1:text;
a,b,c,cv,dt,p:real;
begin
clrscr;
assign(f1,fi); reset(f1);
readln(f1,a,b,c);
if (a>0) and (b>0) and (c>0) then
begin
if (a+b>c) and (a+c>b) and (b+c>a) then
begin
cv:=a+b+c;
writeln('Chu vi=',cv:4:2);
p:=cv/2;
dt:=sqrt(p*(p-a)*(p-b)*(p-c));
writeln('Dien tich=',dt:4:2);
end
else writeln('Vui long nhap lai');
end
else writeln('Vui long nhap lai');
close(f1);
readln;
end.