tast99.py

#Uses python3

import sys

def bigger_than(a, b):
	return (a + b) > (b + a)

def find_biggest_index(a):
	max_index = 0
	for i in range(len(a)):
		if bigger_than(a[i], a[max_index]):
			max_index = i
	return max_index

def largest_number(a):
	answer = ""

	while a:
		biggest_index = find_biggest_index(a)
		answer += a[biggest_index]
		del(a[biggest_index])

	return answer

if __name__ == '__main__':
    a = [ "123", "124", "56", "90", "99", "990"]
    print(largest_number(a))