input_filepath = 'input.txt'

# open input file and make 2 lists of strings
with open(input_filepath) as input_file:
    text = input_file.read()
    two_lists = text.split('\n')
    number_items = two_lists[0]
    list_of_items = two_lists[1].split(' ')

list_of_items = [int(item) for item in list_of_items]

nums = [[item] for item in list_of_items]
indexes = [i for i in range(1, len(nums) + 1)]

print(indexes)

def merge(left, right):
    """Merge two lists in ascending order."""
    lst = []
    while left and right:
        if left[0] < right[0]:
            lst.append(left.pop(0))
        else:
            lst.append(right.pop(0))
    if left:
        lst.extend(left)
    if right:
        lst.extend(right)
    return lst

j = 0
n = len(nums)
indout = []
nums_out = []

while j < n / 2:
    newlst = []
    newind = []
    i = 0
    while i < len(nums):
        print(indexes[i])
        x = merge(nums[i], nums[i + 1])
        nums_out.append(x[0])
        nums_out.append(x[-1])
        newlst.append(x)
        newind.append(indexes[i])
        newind.append(indexes[i + 1])
        indout.append(indexes[i])
        indout.append(indexes[i + 1])
        i += 2

    j += 1
    nums = newlst[:]

    indexes = []
    indexes.append(newind[0])
    indexes.append(newind[-1])

digits = [str(i) for i in nums[0]]
last_line = ' '.join(digits)

all_lines = []
k = 0
while k < len(indout):
    one_line = []
    one_line.append(indout[k])
    one_line.append(indout[k + 1])
    one_line.append(nums_out[k])
    one_line.append(nums_out[k + 1])
    tmp_str = [str(i) for i in one_line]
    all_lines.append(tmp_str)
    k += 2

str_lines = [' '.join(i) for i in all_lines]
answer = '\n'.join(str_lines) + '\n' + last_line
print(answer)