Categorize the days of the week based on their starting alphabet.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday
S - Sunday, Saturday
M - Monday
W - Wednesday
T - Tuesday, Thursday
F - Friday
<START_INST>Categorize the days of the week based on their starting alphabet.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday<END_INST><START_CTX><END_CTX><START_A>S - Sunday, Saturday
M - Monday
W - Wednesday
T - Tuesday, Thursday
F - Friday<END_A>