# -*- coding: utf-8 -*-
"""
Spyder Editor

This is a temporary script file.
"""
import sys

def bidirectional_bubble_sort(a):
    left = -1
    right = len(a)
    while left < right:
        swap = False
        left += 1
        right -= 1
        for i in xrange(left, right):
            if a[i] > a[i + 1]:
                t = a[i]
                a[i] = a[i + 1]
                a[i + 1] = t
                swap = True
        if not swap:
            return
        else:
            swap = False
        for i in xrange(right, left, -1):
            if a[i] < a[i - 1]:
                t = a[i]
                a[i] = a[i - 1]
                a[i - 1] = t
                swap = True
        if not swap:
            return


def main(argv):
    bidirectional_bubble_sort(argv)

if __name__ == "__main__":
    main(sys.argv)