program PhepTinhPhanSo;

type KieuPhanSo = record

       ts, ms: integer;

     end;

{------------------------------------}

{        CHUONG TRINH CON            }

{------------------------------------}

procedure GPS(ps:KieuPhanSo);

begin

  write(ps.ts,'/',ps.ms);

end;

function USCLN(a, b: integer):integer;

begin

  while (a<>b) do

  begin

    if a>b then a:=a - b

    else b:=b - a;

  end;

  USCLN:=a;

end;

procedure ToiGian(var ps: KieuPhanSo);

  var us:integer;

begin

  us:=USCLN(ps.ts,ps.ms);

  ps.ts:=ps.ts div us;

  ps.ms:=ps.ms div us;

end;

procedure CongPS(ps1, ps2: KieuPhanSo; var kq: KieuPhanSo);

begin

  kq.ms:=ps1.ms*ps2.ms;

  kq.ts:=ps1.ts*ps2.ms + ps2.ts*ps1.ms;

  ToiGian(kq);

end;

procedure NhapPS(var ps:KieuPhanSo);

begin

  write('Tu so = '); readln(ps.ts);

  write('Mau so = '); readln(ps.ms);

end;

{------------------------------------}

{        CHUONG TRINH CHINH          }

{------------------------------------}

var

  ps1,ps2,kq:KieuPhanSo;

begin

  writeln('Phan so 1');

  NhapPS(ps1);

  writeln('Phan so 2');

  NhapPS(ps2);

  GPS(ps1);

  write(' + ');

  GPS(ps2);

  write(' = ');

  CongPS(ps1,ps2,kq);

  GPS(kq);

  readln;

end.