import random


def roll_dice(n_rolls):
    """
    1) Create a 6 by 6 two-dimensional list (call it rolls)
       filled with all zeros.
    2) Use a loop that iterates n_rolls times:
        2a) Generate two random numbers in the range 0-5
        2b) Use those numbers as indices to the rolls[][] list
            and add one to the corresponding list entry
    """

    # Initialize a 6 by 6 two-dimensional list
    rolls = [[0 for column in range(6)] for row in range(6)]
    
    #
    for n in range(n_rolls):
        rand1 = random.randint(0,5)
        rand2 = random.randint(0,5)
        
        # Add 1 to the corresponding list entry of 2 random numbers
        rolls[rand1][rand2] += 1
        
    return rolls