https://school.programmers.co.kr/learn/courses/30/lessons/12950
"""
입출력 예시)
arr1 = [[1,2],[2,3]], arr2 = [[3,4],[5,6]] -> [[4,6],[7,9]]
arr1 = [[1],[2]], arr2 = [[3],[4]] -> [[4],[6]]
"""
def solution(arr1, arr2):
answer = []
for i in range(len(arr1)):
arr_sum = []
for j in range(len(arr1[0])):
arr_sum.append(arr1[i][j] + arr2[i][j])
answer.append(arr_sum) # answer[i][j] = arr1[i][j] + arr2[i][j]
return answer