class App {

static private void concatena(String s1, String s2) {
s1 = s1 + s2;
s2 = "";
}

static public void main(String[] args) {
String s1 = "Fundatec";
String s2 = "Concursos";

concatena(s1, s2);

System.out.println(s1 + " " + s2);

}
}