public ArrayList<String> searchFacturas(String mat){
        String dataPath = "./data/facturas";
	String[] years = disco.listarDirectorio(dataPath);
	String[] months, fac;
	ArrayList <String> result = new ArrayList();
	for(int i=0; i< years.length; ++i){
		months = disco.listarDirectorio(dataPath +"/"+ years[i]);
		for(int j=0; j<months.length; ++j){
			fac = disco.listarDirectorio(dataPath +"/"+ years[i] +"/"+ months[j]);
			for(int k=0; k<fac.length; ++k){
				if(fac[k].contains(mat)) 
                                    result.add(dataPath +"/"+ years[i] +"/"+ months[j] +"/"+ fac[k]);
	
                        }
                }
        }
        return result;
    }