https://programmers.co.kr/learn/courses/30/lessons/12901
규칙을 찾아 조건에 따라 구현하면 된다!
def solution(a, b):
array=["FRI","SAT","SUN","MON","TUE","WED","THU"]
counts=[0,31,29,31,30,31,30,31,31,30,31,30,31]
month=0
day=0
for i in range(a-1):
month+=counts[i+1]
day=b-1
return(array[(month+day)%7])