Executing java program with 2 classes

save the file with D.java:

class C {
    int x;
    int y; 
    }

class D {
    public static void main(String args[]) {
        C c1,c2;
        c1 = new C();
        c2 = new C();
        c1.x = 10;
        c1.y = 20;
        c2.x = 6;
        c2.y = 7;
        System.out.println(c1.x+"\t"+c1.y);
        System.out.println(c2.x+"\t"+c2.y);
        } 
        }