a, b, c = list(map(int,input().split()))

candidate = []
for i in range(a+1):
    for j in range(b+1):
        output = 1 * i + 10 * j
        for price in range(1, output+1):
            num_coins = (output - price) // 10 + (output - price) % 10
            if num_coins + (a-i) + (b-j) == c:
                candidate.append(price)
                
if len(candidate) == 0:
    print('Impossible')
else:
    print(min(candidate))