l1 = [1,8,7,2,21,15]
print(l1)

#To sort the list
# l1.sort()
# print(l1)

#To reverse the list
# l1.reverse()
# print(l1)

#To append an  element at the end of a list
# l1.append(99)
# print(l1)

#To insert an element at a particular index
# l1.insert(0,545)
# print(l1)

#To pop an element at a particular index
# l1.pop(2)

# removes 21 from the list
l1.remove(21)
print(l1)