gistfile1.py

#!/usr/bin/env python

def count_down_up(max):
    countdown = "-".join("x" * (max - i) for i in range(max)) + "-"
    countup   = "-".join("x" * i         for i in range(1, max+1)) + "-"
    overlaps = 0
    for i in range(min(len(countup), len(countup))):
        if countdown[i] == "-" and countup[i] == "-":
            overlaps += 1
    return overlaps, countdown, countup

from sys import argv
max = 0
for i in range(1, int(argv[1])):
    overlaps, countdown, countup = count_down_up(i)
    if overlaps >= max:
        max = overlaps
        print "Overlapping %d time%s:" % (max, "s"[:int(max != 1)])
        print countdown
        print countup
        print