Three-dimensional list in Python

A three-dimensional list looks like this:

lst = [
	[
		['a', 'b'],
		['c', 'd'],
	],
	[
		['e', 'f'],
		['g', 'h'],
	],
	[
		['i', 'j'],
		['k', 'l'],
	]
]

To display elements from such a list, you need to write three square brackets:

print(lst[0][0][0]) # 'a'
print(lst[2][1][0]) # 'k'

The following list is given:

lst = [
	[
		['a', 'b'],
		['c', 'd'],
	],
	[
		['e', 'f'],
		['g', 'h'],
	]
]

Print the string 'acfg' from it.

The following list is given:

lst = [
	[
		[1, 2],
		[3, 4],
	],
	[
		[5, 6],
		[7, 8],
	],
]

Find the sum of all elements in the given list.