classmates=["tan", "mike", "elena"]#this is a list
classfriends=("tan", "mnike","elena")#this is a tuple
L = [
    ['Apple', 'Google', 'Microsoft'],
    ['Java', 'Python', 'Ruby', 'PHP'],
    ['Adam', 'Bart', 'Lisa']
]
print(L[0][0])
print(L[1][1])
print(L[2][2])
