a, b, c = map(int, input().split())
for i in range(1, a + 10 * b + 1):
    for j in range(a + 1):
        for k in range(b + 1):
            s = j + 10 * k
            if s < i:
                continue
            r = s - i
            if a + b - j - k + r // 10 + r % 10 == c:
                print(i)
                exit()
print('Impossible')