var m,p,g,tbm: real;

begin

    writeln('nhap diem Mieng: ');

    read(m);

    writeln('nhap diem 15 phut: ');

    read(p);

    writeln('nhap diem Giua ky: ');

    read(g);

    tbm = ( m + 2*p + 2*g)/3

    if (tbm >= 8) then

         writeln('diem TBM la:', tbm ,' xep loai Gioi');

    else if ( tbm > 6.5 and then tbm < 8) then 

         writeln('diem TBM la:', tbm ,' xep loai Kha');

    else if ( tbm > 5 and then tbm < 6.5) then 

         writeln('diem TBM la:', tbm ,' xep loai TB');

    else

         writeln('diem TBM la:', tbm ,' xep loai Yeu');

    readln;

end.

var x, i : integer;

begin

     writeln('nhap so nguyen x : ')

     read(x);

     if ( x < 2) then writeln(' x khong phai so nguyen to');

     else if ( x > 2) then

        begin

              for i := 2 to ( x - 1) do

                  begin

                     if ( x mod i = 0) then writeln(' x khong la so nguyen to');

                  end;

        end;

    else

        writeln(' x la so nguyen to');

    readln;

end.

B

var t,v,a,dtb: real;

begin

    writeln(' diem mon Toan la: ');

    read(t);

    writeln(' diem mon Van la: ');

    read(v);

    writeln(' diem mon Anh la: ');

    read(a);

    dtb = ( t + v + a)/3

    if ( dtb >= 5 ) then 

           writeln(' duoc len lop');

    else

           writeln(' thi lai');

    readln;

end.

var m,n: integer;

begin

    writeln(' nhap so nguyen a: ');

    read(a);

    writeln(' nhap so nguyen b: ');

    read(b);

    writeln((m + n)/2);

    readln;

end.

var a,b : integer;

begin

      writeln('nhap so nguyen a:');

      read(a);

      writeln('nhap so nguyen b:');

      read(b);

      if ( a*b >= 0) then

           writeln(' a va b cung dau');

      else

           writeln('a va b khac dau');

     readln;

end.