import copy
import itertools
max = 0
ostatki = []
n = int(input())
chisla = map(int, input().split())
oldallresults = []
somechisl = ""
for i in range(1, n + 1):
    newlist = copy.deepcopy(chisla)
    result = itertools.combinations(newlist, i)
    oldallresults.extend(result)

for i in range(len(oldallresults)):
    for j in oldallresults[i]:
        somechisl = str(somechisl) + str(j)
    intsomechisl = int(somechisl)
    if intsomechisl % 15 == 0 and intsomechisl > max:
        max = intsomechisl
    somechisl = ""

if max != 0:
    print(max)
else:
    print("Impossible")