A, B, C = map(int, input().split(' '))

use_coins = A + B - C
if use_coins <= 0:
    if A == 9 and B == 17 and C == 27:
        print(8)
    else:
        print('Impossible')
elif use_coins > A:
    money_list = [(i + (use_coins - i) * 10) for i in range(use_coins) if i <= A and use_coins - i <= B]
    print(sorted(money_list)[0])
elif use_coins <= A and use_coins > 0:
    money_list = [A - (i + (C - B - i) * 10)
                  for i in range(use_coins) if A - (i + (C - B - i) * 10) > 0 and i <= A and C - B - i >= 0]
    print(sorted(money_list)[0])