s_1 = input("输入第一段英文:")
s_1 = [i.strip('.').strip(',').strip('!').strip('"') for i in s_1.lower().split(" ")]
s_1 = set(s_1)
s_2 = input("输入第二段英文:")
s_2 = [i.strip('.').strip(',').strip('!').strip('"') for i in s_2.lower().split(" ")]
s_2 = set(s_2)
list_inter = list(s_1.intersection(s_2))
print(list_inter)