一道简单递归题

@Test
public void main() {
    System.out.println(this.calsum(5));
}
public  int calsum(int a){
    System.out.println(a);
    if(0<a){
        System.out.println(a+"111");
        return calsum(a-2)+2;
    }
    System.out.println();
    return 1;
}