S = 'Impossible'

a, b, c = map(int, input().split())
n = a + b
ans = 0

# 枚数を増やす場合
if n <= c:
    dist = c - n
    if dist > 8 or b == 0:
        print(S)
        exit()
    else:
        ans = 9 - dist

# 枚数を減らす場合
else:
    dist = n - c

    # 1 -> 10 両替
    x1 = dist // 9
    x2 = (a - 1) // 10
    x = min(x1, x2)
    a -= x * 10
    b += x
    n = a + b
    dist = n - c

    if dist < a:
        ans = dist
    else:
        dist -= a
        ans = a + dist * 10

print(ans)