public class COS_JavaTest {
    private int q = 0;
    public int add(int x, int y) {
	return x+y;
    }
    public int sub(int x, int y) {
	return x-y;
    }
    public int mult(int x, int y) {
	return x*y;
    }
    public int addmult(int x, int y, int z) {
	return add(x,mult(y,z));
    }
    public void set(int x) {
	q = x;
    }
    public int get() {
	return q;
    }
    public int fact(int x) {
	return (x>0)?(x*fact(sub(x,1))):1;
    }
}