public boolean sLeft(){
		boolean change = false;
		
		//i -> y | j -> x
		for (int i = 0 ; i < 4 ; i ++){
			for (int j = 0; j < 4 ; j++) {
				if(mLeft(j, i))
					change = true;
			}
			if (aLeft(i))
				change = true;
		}
		if (change){
			//System.out.println(change);			//debug
			genTile();
		}
		return change;
	}