The books need to go in the backpack. Draw the path starting at 2 and counting by 2's up to 200.

			2	4	6	8	18	20
			68	66	64	10	16	22	24
			70	72	62	12	14	28	26
114	112	78	76	74	60	42	40	30	32
116	110	80	82	84	58	44	38	36	34
118	108	106	104	86	56	46	48	190	192
120	126	128	102	88	54	52	50	188	194
122	124	130	100	90	176	178	184	186	196
140	138	132	98	92	174	180	182	200	198
142	136	134	96	94	172	170
144	146	152	154	160	162	168
	148	150	156	158	164	166