merge_sort() begin. input:
input1 (22)
input2 (7)
input3 (2)
input4 (1)
input5 (8)
input6 (4)
	merge_sort() begin. input:
	input1 (22)
	input2 (7)
	input3 (2)
		merge_sort() begin. input:
		input1 (22)
		merge_sort() end. returning single element
		merge_sort() begin. input:
		input2 (7)
		input3 (2)
			merge_sort() begin. input:
			input2 (7)
			merge_sort() end. returning single element
			merge_sort() begin. input:
			input3 (2)
			merge_sort() end. returning single element
		merge_sort() end. returning:
		input3 (2)
		input2 (7)
	merge_sort() end. returning:
	input3 (2)
	input2 (7)
	input1 (22)
	merge_sort() begin. input:
	input4 (1)
	input5 (8)
	input6 (4)
		merge_sort() begin. input:
		input4 (1)
		merge_sort() end. returning single element
		merge_sort() begin. input:
		input5 (8)
		input6 (4)
			merge_sort() begin. input:
			input5 (8)
			merge_sort() end. returning single element
			merge_sort() begin. input:
			input6 (4)
			merge_sort() end. returning single element
		merge_sort() end. returning:
		input6 (4)
		input5 (8)
	merge_sort() end. returning:
	input4 (1)
	input6 (4)
	input5 (8)
merge_sort() end. returning:
input4 (1)
input3 (2)
input6 (4)
input2 (7)
input5 (8)
input1 (22)