l1=[1,7,8,21,4,15,6]
# print(l1)
# l1.sort() sort list
# l1.reverse() reverse list
#l1.append(45) #adds att end of List
l1.insert(2,100) # Insert 2 at index
l1.pop(4)#remove
l1.remove(15) #remove
print(l1)