result=[]
first=0;second=0
for first in range(len(list_data)):
for second in range(len(list_data)):
result.append(str(list_data[first])+str(list_data[second]))
# ==================================return result
하니 결과가 잘 나오는데 과제를 제출하면 Failed뜨네요! 뭐가문제죠??