def find_post(pre_str: str, mid_str: str) -> str:
if not pre_str:
return ""
post_str = ""
root_in_mid = mid_str.find(pre_str[0])
ltree_rlimit = 0
for item in mid_str[:root_in_mid]:
locate = pre_str.find(item)
if ltree_rlimit < locate:
ltree_rlimit = locate
root_in_mid = mid_str.find(pre_str[0])
# ltree
post_str += find_post(pre_str[1:ltree_rlimit + 1], mid_str[:root_in_mid])
# rtree
post_str += find_post(pre_str[ltree_rlimit + 1:], mid_str[root_in_mid + 1:])
post_str += pre_str[0]
return post_str
def func():
# please define the python3 input here.
# For example: a,b = map(int, input().strip().split())
pre_visit = input().strip()
mid_visit = input().strip()
# please finish the function body here.
post_visit = find_post(pre_visit, mid_visit)
# please define the python3 output here. For example: print().
print(post_visit)
if __name__ == "__main__":
func()
