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

    for price in range(1, a + 10 * b + 1):
        # 1Gコインをx枚，10Gコインをy枚使って払う
        for x in range(a + 1):
            for y in range(b + 1):
                pay = x + 10 * y
                if pay < price:
                    continue
                # お釣り
                back = pay - price
                if c == a - x + b - y + back % 10 + back // 10:
                    print(price)
                    exit()
    print("Impossible")


if __name__ == "__main__":
    main()