EchoTestDrive.java

public class EchoTestDrive {
	public static void main(String[] args) {
		Echo e1 = new Echo();
		Echo e2 = new Echo();
		int x = 0;
		while (x<4) {
			e1.hello();
			// 0-1 1-2 2-3 3-4
			e1.count = e1.count + 1;
			if (x>0) {
				// 0-0 1-1 2-2 3-6
				e2.count = e2.count + 1;
			}
			if (x>1) {
				// 0-0 1-0 2-5 3-10
				e2.count = e2.count + e1.count;
			}
			x = x + 1;
		}
		System.out.println(e2.count);
	}
}

class Echo {
	int count = 0;
	void hello() {
		System.out.println("helloooo... ");
	}
}