MergeSort

def merge(first, second):
    result = []
    i = 0
    j = 0
    while i < len(first) and j < len(second):
        if first[i] <= second[j]:
            result.append(first[i])
            i += 1
        else:
            result.append(second[j])
            j += 1
    while i < len(first):
        result.append(first[i])
        i += 1
    while j < len(second):
        result.append(second[j])
        j += 1
    return result


def merge_sort(arr):
    if len(arr) == 1:
        return arr
    l = len(arr)
    first = merge_sort(arr[0:(round(l/2))])
    second = merge_sort(arr[round(l/2):l])
    return merge(first, second)

a = [10, 5, 6, 3, 2, 1, 9, 0, 12, 13, 23, 124,124,534,2345,534,234,12312,423412,546,2342,234,45,54,234]
b = merge_sort(a)
print(b)