uses crt;
var a,b:integer;
begin
clrscr;
repeat
write('Nhap nam sinh cua cha:'); readln(a);
write('Nhap nam sinh cua con:'); readln(b);
until (0<a) and (0<b) and (a>b) and (a<=2020) and (b<=2020);
writeln('Sau 10 nam nua cha ',a+10,' tuoi');
writeln('Sau 10 nam nua con ',b+10,' tuoi');
readln;
end.