#classmates = ['Michael', 'Bob', 'Tracy']
#a = len(classmates)
#b = 0
#c = classmates[b]
#print ('总长度%d,第%d个是%s' % (a, b+1, c))
# -*- coding: utf-8 -*-

L = [
    ['Apple', 'Google', 'Microsoft'],
    ['Java', 'Python', 'Ruby', 'PHP'],
    ['Adam', 'Bart', 'Lisa']
]

print(L[0][0])
print(L[1][1])
print(L[2][2])
