A, B, C = map(int, input().split())

ans = []
for i in range(0, A + 1):
    # 1G
    for j in range(0, B + 1):
        # 10G
        budget = i + 10*j
        # 1G ~ budget G の商品なら買える
        # k G の商品を買うとする
        for k in range(1, budget + 1):
            change = budget - k
            sho, amari = divmod(change, 10)

            # 残りの硬貨の枚数は
            nokori = A + B - (i + j) + (sho + amari)
            if nokori == C:
                ans.append(k)
if ans:
    print(min(ans))
else:
    print('Impossible')