4/1	4/8	4/15	4/22
S1	S1	S2	B
S1	S1	P	S2
S1	S1	S2	B
S1	S1	S2	P
S1	S1	S2	B

5/6	5/13	5/20	5/27
S1	S1	S3	P
S1	S1	S3	B
S1	S1	S3	P
S1	S1	S3	B
S1	S1	S3	P