x, y, z = map(int, input().split())
sum = x + 10 * y
y_10, x_10 = divmod(sum, 10)
if x == z and y ==0:
    print('Impossible')
    exit()
if x + y + 10 < z:
    print('Impossible')
    exit()
if y>z:
    print((y-z) * 10 + x)
else:
    change_count = (z-y_10)//9 + 1
    print(y_10 - change_count + x_10 + change_count*10-z)