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

for money in range(1, 300):
    for ai in range(a + 1):
        for bi in range(b + 1):
            if money > ai + bi * 10:
                continue
            diff = (ai + bi * 10) - money
            ret = diff % 10 + diff // 10
            if a + b + ret - ai - bi == c:
                print(money)
                exit()
print("Impossible")