uses crt;
var a,b,c,d:integer;
procedure nhap;
begin
writeln('nhap phan so thu nhat');
write('tu so: '); readln(a);
write('mau so: '); readln(b);
writeln('nhap phan so thu hai');
write('tu so: '); readln(c);
write('mau so: '); readln(d);
end;
begin
nhap;
mc:=b*d;
Tutong:=a*d+b*c;
Tuhieu:=a*d-b*c;
write('tong=',tutong,'/',mc);
write('hieu=',tuhieu,'/',mc);
readln;
end.