class IntList{
	int [] data;
	int len =0;

	IntList(int len) {
		data = new int[Math.max(1,len)];
	}

	IntList() {
		data = new int[16];  // some default size
	}
	void add(int elem) {
		if (len == data.length-1) {
			int [] b = new int [data.length*2];
			System.arraycopy(data,0, b,0,data.length);
			//for (int i = 0; i < data.length; i++) b[i] = data[i];
			data =b;
		}
		data[len++] = elem;
	}// end add

	void addAt (int elem, int pos) {
		while (pos > data.length) {
			int [] b = new int [data.length*2];
			for (int i = 0; i < data.length; i++) b[i] = data[i];
			data =b;
		}
		data[pos] = elem;
	} // end addAt


	void clear(){
		len =0;
	} // end clear;

	int get (int pos){
		if (pos > len-1 ) return -1; else return data [pos];
	}//end get

	int size() {
		return len;
	}//end size
} // end class IntList