uses crt;
var a,b,c,tb,kq:real;
begin
        clrscr;
        write('Nhap vao ba so a,b va c: ');read(a,b,c);
        tb:=(a+b+c)/3;
        kq:=sqrt(tb);
        writeln('Can bac 2 cua trung binh cong 3 so a,b va c la: ',kq:10:2);
        readkey;
end.