var  a, b, c, p: integer; 
   r,s : real;
begin  
write(' a, b, c= ');
readln(a, b, c);
p:=a+b+c; 
r:=p/2;
s:=sqrt(r*(r-a)*(r-b)*(r-c));
writeln ('s=', s,   '   p=', p);
end.